Art. LXV.—On a Deposit of Moa-bones at Kapua.
[Read before the Philosophical Institute of Canterbury, 7th August, 1895.]
In September, 1895, a paragraph appeared in a local newspaper stating that some moa-bones had been found in South Canterbury. I therefore visited the place, which was at the Kapua Settlement, near the head of Waimate Gorge. The bones had been found when sinking a well, and, after having satisfied myself by probing that there were a large number of them, I secured for the Canterbury Museum the right of digging them out. Being obliged to return to Christchurch, owing to the University session not being over, I sent Mr. W. Sparkes, taxidermist, to superintend the excavations, which he did in a most satisfactory manner, the result being the largest and most varied collection of moa-bones ever obtained from one place. The remains of carinate birds were few, and none of them belonged to still-living species.
A large number of badly-preserved and young bones were left on the ground, and of those which arrived at the Museum many were rejected as not sufficiently perfect to admit of measurement. After this was done there remained the following:—
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If we allow half as many again for the discarded bones we have a total of 1,123 metatarsi, representing probably not less than 800 birds. It will be noticed that more than half the bones belong to Meionornis. Next come Euryapteryx and Dinornis; while Pachyornis is only half as numerous as the two latter genera. This is very different from the collection I obtained for the Otago Museum from Hamilton's, where, out of 176 metatarsi, 57 belonged to Euryapteryx, 52 to Pachyornis, 32 to Meionornis, and 26 to Dinornis, the most abundant species being Pachyornis elephantopus.
Mode of Occurrence of the Bones.
The hills north-west of Waimate send out a spur in a southerly direction to the Waihao River. This spur is crossed by a narrow gorge, known as the Waimate Gorge, which, after crossing the spur, opens out into a plain, about three miles long and one mile broad, at a distance of four miles from Waimate. This is the basin of a former lake, which was drained by the stream which runs through Waimate Gorge. To the north the plain is bounded by Palæozoic or Older Mesozoic hills, and on the south by a low, narrow ridge of Tertiary rocks, which separates it from the valley of the Waihao River. The plain is about 300ft. above the sea, and the valley of the Waihao is about 100ft. lower. When the settlers first came to the place the lake was not quite dry, for a small pond still remained close to its former exit, at the entrance to the gorge. This pond has been lately drained, and it was there where the bones occurred. The drain, which was 7ft. deep, did not disclose a single bone, although there are bones on both sides of it in patches. The patch dug out for the Museum was on the eastern side of the Government drain, and was on the section belonging to Mr. T. A. McDonald. The area excavated was 30ft. by 20ft., and the section was as under:—
Pale-yellow clay, 4ft. thick, soft and wet in places. No moa-bones.
Black sandy clay, 1 ½ft. thick, with a few moa-bones.
Tough blue clay, 4ft. to 5ft., full of moa-bones.
Below the patch of bones the blue-clay still continued downwards, but without any bones in it. The bones were mixed, as usual, with large quantities of moa-stones—chiefly of white quartz—of all sizes, from mere sand up to pebbles 1 ½in. in diameter, thus proving that the bodies of the moas were floated into the lake before decomposition. No large timber, or other evidence of floods, was found; only a few small sticks here and there. There were large numbers of bones of young moas; but no egg-shell was found, nor any land or freshwater Mollusca.
The origin of this old lake is very obscure. There are no extinct volcanoes in the neighbourhood, and there is no evidence of the former existence of a glacier. An unequal movement of the land appears to be the most probable cause; but, be this as it may, it is evident that it was only during a portion of the lake's history that the bodies of moas were floated into it and buried in mud. It is possible, but not probable, that no moas lived near the lake before that period, but certainly they lived there afterwards, although none were buried in the lake. Consequently we must suppose that different climatic conditions prevailed during the time the moa-deposit was formed from that which followed, and, probably, from that which preceded it also. The burying of the moas was, most probably, due to floods, caused either by heavy rain or by the rapid melting of snow; and if trees were also washed into the lake they must have floated to a greater distance than the moas—perhaps out of the lake altogether. The peaty layer above the bones seems to show that the diluvial epoch was followed by a specially dry epoch, which allowed vegetable growth to accumulate on the bottom of the lake; and the dry epoch was succeeded by the present one. Evidently the bone-deposit is an old one.
Specific Characters in the Dinornithidæ.
Whenever we find an anatomical structure tolerably constant in the moas we nearly always find it exhibited by bones of very different sizes—so different, indeed, that we cannot suppose the two birds to which the bones belonged to have stood in the relation to each other of parent and offspring. If, therefore, the term “species” can be defined as a group of individuals which resemble each other as much as parents resemble their offspring it is evident that we have two or more species belonging to the same genus, and that the peculiar anatomical structure is of generic value. When, however, we come to look for other characters except size to distinguish between the species we generally find that the subordinate anatomical characters are so variable that they cannot be relied on for specific diagnosis, and we have therefore to fall back upon measurements of the bones. In fact, structural characters, when not of generic importance, are merely individual variations which are not transmitted. But there is often in each series a complete set of connecting links between the largest and the smallest bones, so that we feel doubtful where to draw the dividing-line. In my former paper on the moas of New Zealand* I took individual skeletons, or parts of skeletons, as guides for arranging the other bones into
[Footnote] * Trans. N.Z. Inst., vol. xxiv., p. 93.
species; but the present large collection—all from one place—enables me to pursue another system, and to ascertain which bones belong to different species by the method of averages. The advantage is that we thus find the commonest or most typical form of each species, while by the former method we may be taking an exceptional bird as our guide.
The result of my examination is to show that, although the species do, undoubtedly, often pass into each other, still the connecting links are comparatively rare, while the main body of the individuals of a group are well separated from the main body of individuals of another group; or, in other words, the individuals form clusters with only a few connecting links. These clusters or groups I take to be species; and this has made me abandon the following specific names formerly proposed by me, although some of them may, perhaps, have to be used in the future as varietal names: Dinornis validus, potens, and strenuus; Palapteryx plena; Euryapteryx compacta; and Pachyornis valgus.
The classification of the moas has been further complicated by the idea that the sexes must have been of different sizes. This idea, discussed and rejected by Sir Richard Owen,* was again brought forward by Sir Julius von Haast, and was subsequently developed by Mr. R. Lydekker. It has, however, no positive evidence in its favour, but, as Mr. Lydekker himself says, is an inference from the case of the Apterygidœ, in which the females are larger than the males. But the measurements which I have made of 2,010 leg-bones of the Dinornithidœ by no means confirm this inference; on the contrary, they show distinctly that, in several species at least, sexual differences of size are very slight, if any; and this result I take to be the most important part of my investigation. The evidence for this statement will be given in the remarks on the species, but it will save much repetition if I here give an outline of the reasoning employed.
In the first place, if the sexes of a species are of different sizes, these two sizes will be more numerous than other sizes which are individual variations from the average, and a species would consist of two groups or clusters. But we must remember that this might also be due to the existence of two varieties of different sizes, too closely connected by intermediate sizes to allow us to call them separate species.
In the second place, we may fairly assume that the sexes lived together and had the same habits. If the moas were monogamous—as are the kiwi, the emu, and the cassowary—we should expect each sex to be equally numerous. If, however, they were polygamous—as are the rhea and ostrich—
[Footnote] * Trans. Zool. Soc. of London, vol. iii., p. 252.
then the females would outnumber the males, but we should expect to find the same proportion between the sexes maintained in each locality. On the other hand, two varieties of a species might, very probably, have different geographical distributions or different habitats. This may enable us to distinguish between varieties and sexes, and to test the validity of supposed species.
In the third place, we may assume that if a considerable difference in size between the sexes existed in one species it existed in all belonging to the same genus; and, vice versâ, if there was no sexual difference of size in one species, probably there was not much difference in others. Consequently, if two different sizes of a species occur frequently, they are probably due to sexual differences; if, however, this only occurs occasionally, it is probably due to the existence of two varieties.
Another important result of these measurements is to show that of all the leg-bones the tibio-tarsus is the least variable and gives the best specific characters.
Explanation of the Diagrams.
While a knowledge of the width at the extremities of the limb-bones is necessary for their generic determination, the specific characters chiefly depend on the length and on the width of the shaft in the middle. I have therefore drawn a set of diagrams showing both of these measurements and also the number of bones agreeing with them, these being expressed by numbers in the squares; consequently these diagrams give the length and mid-width of each of the 2,010 bones which I measured. An examination of them will show what I mean by the bones being arranged in clusters; generally with one, but occasionally with two, points of concentration within what I take to be a specific area. It will be noticed that it is only occasionally that the lines defining the species are arbitrarily drawn—usually there is a distinct indication of a break. My greatest difficulty has been to distinguish between the leg-bones of Euryapteryx crassa and those of Meionornis casuarinus. The leg-bones of these two species pass completely into each other, and in drawing the line of division I have been guided by the proportionate numbers of skulls and sterna of Meionornis and Euryapteryx respectively. Taking these as guides, I have divided the leg-bones into somewhat similar proportions; and although, doubtless, some bones of crassa are included in casuarinus, and some of the latter in crassa, I do not think that it affects the general results much, and it cannot invalidate the conclusions arrived at as to the average dimensions of the leg-bones in each species.
In some doubtful cases I have been guided by the proportionate numbers of the other bones of the leg. For example, the tibiæ in Dinornis are more easily separated into three groups than are the femora or the metatarsi, and so I have taken them as a guide for the other bones.
In my paper on the axial skeleton of the Dinornithidœ* I have given the generic characters of the vertebral column, pelvis, and sternum; in the present paper, therefore, I have only mentioned those of the limb-bones; and the table at the end gives the average dimensions of these bones, in millimetres, for each species.
The femur is distinguished by its short head and the flat internal trochanterial surface. The shaft is usually round in transverse section, but sometimes flattened from front to back. The linea aspera is broken and often not well marked. The popliteal depression is short and rather deep; the two rough tuberosities (for the heads of the gastrocnemius?) are separated by a smooth longitudinal groove. The distal intercondylar fossa is deep on the inside, shallow and broad on the outside.
The tibia has a length of 12 to 13 times its width in the middle of the shaft. The shaft is long and slender, often slightly curved, and its antero-outer surface is convex in the middle. The extensor bridge and its tubercle are directed above the top of the outer condyle.
The metatarsus has a length of more than 7 times the width in the middle. The proximal articular surface has its inner margin nearly straight and its outer margin rounded. The second trochlea is short, not much longer than the fourth, and its base is broader than that of the fourth.
None of the scapulo-coracoids showed any trace of a glenoid cavity, but several have a depression on the inner side at the anchylosis of the two bones, which might perhaps lead to a mistake. The only cases of a supposed glenoid cavity are those reported by Mr. H. O. Forbes,† and, as both these bones are in his possession, I cannot offer an opinion on them.
D. maximus and D. altus, Owen.
D. maximus (female only), Lydekker.
D. maximus and D. validus, Hutton.
The number of leg-bones measured was—metatarsi, 30;
[Footnote] * Trans. N.Z. Inst., vol. xxvii., p. 157.
[Footnote] † Nature, 14th January, 1892.
tibiæ, 31; femora, 25. The femur, relatively to the tibia, is rather shorter than in the two next species, being considerably less than half its length. The diagrams show that D. maximus and D. robustus are closely connected: the separation is fairly distinct in the tibiæ, but it is not possible always to distinguish the metatarsi and femora of each. Nevertheless, as the difference in size between the typical D. maximus and the smaller form of D. robustus—called by me D. potens—is about one-third, we cannot suppose them to belong to a single species. Mr. Lydekker supposes that this species is the female of D. robustus; but the distribution of the forms is against the idea. At Glenmark and at Enfield the remains of D. maximus were nearly three times as numerous as those of D. robustus. At Kapua they were about equal, and at Hamilton D. maximus was not represented at all.
The metatarsi and femora show one point of concentration only, but with the tibiæ there are two, one of which has a length of 31in., the other of 33in. It is possible that these may indicate sexual differences, but more probably they are varietal. The femur varies very much in thickness, and some of those included under D. robustus may belong here.
The sternum has a breadth just below the costal border of 8.5in. to 9in.
The pelvis has a length of 24in.; the breadth at the antitrochanters is 10.5in.; and the depth of the pre-acetabular part of the ilium is 7.5in. to 8in.
D. robustus, Owen.
D. maximus (male), Lydekker.
D. robustus and D. potens, Hutton.
The number of leg-bones measured was—metatarsi, 39; tibiæ, 35; femora, 40. The femur is about half the length of the tibia. The sternum has a width of 7in. to 8in. just below the costal border. The pelvis has a length of about 21in.; its width at the antitrochanters is 10in.; and the depth of the antacetabular portion of the ilium is 6.5in.
The diagrams of this species show that not only do the tibiæ concentrate on two points, with lengths of 30in. and 27in. respectively, but the femora also show a slight tendency to a double concentration. This may be due either to sexual differences or to the existence of two sub-species. If the first is the true explanation it is probable that the smaller form (potens) is the female, for an individual of this size was found, in 1861, at Tiger Hill, accompanied by four half-grown chicks.
D. struthioides (part), Owen.
D. gracilis and D. struthioides, Haast.
D. sp. (robustus) and D. struthioides (part), Lydekker.
D. torosus, D. strenuus, and Pal. plena, Hutton.
The number of leg-bones measured was—metatarsi, 55; tibiæ, 33; femora, 35. The sternum has a width of 5.5in. to 6.2in. just below the costal border. The length of the pelvis is about 17in.; its width at the antitrochanters 8in.; and the depth of the antacetabular portion of the ilium about 5in.
This species is well marked off from D. robustus, and I was evidently quite wrong in subdividing it. There are not two sizes, but each bone shows a single point of concentration. Here, therefore, we have good evidence that the two sexes were practically identical in size, and consequently it is probable that the same held good with the larger species of Dinornis. Certainly it does away with any argument based on the different sizes of the sexes in Apteryx.
The femur has a short head with slightly constricted neck. The shaft is slender, slightly compressed laterally in the middle, and the anterior surface is curved longitudinally in the antero-posterior plane. The linea aspera is well marked, but the popliteal tuberosities are obsolete. The popliteal depression is short and shallow. The distal intercondylar fossa is deep on the inside and shallow on the outside.
The length of the tibia is 12 to 14 times its width in the middle. The procnemial ridge is nearly straight. The shaft is convex both before and behind, and is more nearly oval in transverse section than in any other genus. The extremities are but slightly expanded, and the extensor bridge and tubercle are directed above the top of the outer condyle.
The length of the metatarsus is between 6 and 7 times the width in the middle. The proximal articular surface has both its inner and outer margins rounded. The foramina above the insertion of the tibialis anticus usually open anteriorly into a deep depression, and their posterior openings are nearer together than in other genera. The posterior surface of the shaft is more rounded than in any other genus. The trochleæ diverge strongly: the second is short, its outer surface with a deep depression, and its base markedly broader than that of the fourth. The two trochlear gorges are of about equal depth.
M. tenuipes and M. hectori (female), Lydekker.
Only two metatarsi and a dorsal vertebra were found. The dimensions of the best-preserved metatarsus are given in the table; the other was smaller, having a length of 185mm.
M. hectori, Haast.
M. hectori (male), Lydekker.
Of this species there was one complete and well-preserved leg, the dimensions of which are given in the table. It is larger than the type, but has the same slim character; while M. tenuipes is stouter, and has a relatively shorter metatarsus. The perforation in the groove between the third and fourth metatarsal bones, which is given by Sir Julius von Haast as a generic character, is not constant.
In the femur the head is moderately long and the neck much constricted below. The internal trochanterial surface is deeply concave, sometimes even excavated. The shaft is slender and rounded in transverse section; the linea aspera is well marked, rarely broken. The popliteal depression is short and rather shallow; the two tuberosities are confluent and situated at the apex of the depression. The distal inter-condylar fossa is deep on the inside, variable on the outside.
The length of the tibia is 10 to 12 times its mid-width. The shaft is slender and straight; its antero-outer surface flattened in the middle. The distal extremity is moderately expanded inwards; the bridge and tubercle directed towards the inner condyle.
The metatarsus has a length of 4 to 5 times its mid-width. The proximal articular surface has the inner margin ridged in the middle. The proximal interosteal foramina open anteriorly into a deep depression, on the inner margin of which there is a small rough tubercle. There is often a distal interosteal foramen in the groove between the second and third metatarsal bones, and occasionally one between the third and the fourth. The trochleæ do not diverge very widely: the second is longer than in the other genera; its outer surface has only a shallow depression, and its base is narrower than that of the fourth. The gorge between the second and the third is not so deep as that between the third and the fourth.
Dinornis casuarinus and D. rheides, Owen.
Meionornis casuarinus, Haast.*
Anomalopteryx casuarina, Lydekker.
Syornis casuarinus and S. rheides, Hutton.
The number of leg-bones measured was—metatarsi, 327; tibiæ, 301; femora, 276. The sternum has a width below the costal border of 5.2in. to 6.8in. The pelvis has a length of 16in. to 18.5in.; the width at the antitrochanters is 8in. to 9.7in.; and the depth of the pre-acetabular portion of the ilium is 4.7in. to 5in.
I have already explained that the line drawn between the leg-bones of this species and those of E. crassa is artificial, as the two overlap. The large number of bones of this species proves clearly that there are not two sizes, for there is only a single point of concentration in each bone.
If the metatarsus is the type of D. rheides, then it is the largest form of M. casuarinus. In all probability the skull with neck in the Wellington Museum, referred to by Professor Parker as Mesopteryx, sp. b,† belongs to it, and perhaps, therefore, we should be justified in considering it as a good species, for the skull seems sufficiently distinct.
Dinornis huttonii and D. didinus, Owen.
Meionornis didiformis, Haast.
Anomalopteryx didiformis (part) and A. didina, Lydekker.
Mesopteryx didina, Hutton.
The number of leg-bones measured was—metatarsi, 72; tibiæ, 68, femora, 66. The width of the sternum below the costal border is 4in. to 4.5in. The length of the pelvis is about 15.5in.; and its width at the antitrochanters is about 7in.
Here, again, we have only a single point of concentration in each bone, showing that there was no difference in size between the sexes. The tibia is well marked off from that of M. casuarinus, but the other two bones show many intermediate varieties. However, M. didinus is distinguished from M. casuarinus by its relatively longer metatarsus. The two cannot be different sexes of one species, because their distribution is so different. At Enfield, M. didinus was far more
[Footnote] * In Euryapteryx rheides, Haast, the metatarsi alone belong to D. rheides; the rest of the skeleton is partly M. didinus and partly P. inhabilis.
[Footnote] † Trans. N.Z. Inst., vol. xxv., p. 4, pl. i.
abundant than M. casuarinus, while exactly the opposite was the case at Hamilton, Kapua, and Glenmark. Moreover, bones of M. didinus were common in the cave at Castle Rock, Southland, explored by Mr. A. Hamilton,* while M. casuarinus was not even represented. It is therefore almost impossible that they could have been male and female of one species.
In the femur the head is long and rises nearly as high as the trochanter; the neck is slightly constricted below. The internal trochanterial surface is concave or excavated. The shaft is very variable in shape, usually flattened from front to back, but sometimes it is laterally compressed; the linea aspera is not well defined. The popliteal depression is moderate, the two tuberosities confluent or nearly so, chiefly situated at the apex of the depression. The distal extremity is much expanded, and the intercondylar fossa is very deep on both sides. The following characters distinguish it from the femur of Meionornis: The head is longer and rises more rapidly, the anterior surface of the shaft is flatter, and the distal end is more expanded.
The length of the tibia is between 8 ¾ and 11 times the width of the shaft in the middle. The shaft is straight and stout, the proximal posterior surface concave; the antero-outer surface flattened in the middle. The distal extremity is less expanded inwards than in Pachyornis, and is nearly always less than 3.3in. in width.
The length of the metatarsus is between 3 ¾ and 4 ¾ times the width of the shaft in the middle, which is nearly the same in all three bones of the leg. The proximal articular surface has the inner margin nearly straight (except in crassa). The proximal interosteal foramina open anteriorly into a deep depression, on the inner margin of which there is usually a rough tubercle. The trochleæ diverge moderately; the second is long, with a shallow depression on the outer surface, its base is narrower than that of the fourth, but its anterior surface is as broad as that of the third, which does not project forward so much as in Pachyornis.
In the Dunedin Museum there are two complete feet of E. gravis, and in the Christchurch Museum there is a complete foot of E. ponderosa and another of E. crassa, all obtained from the sandhills at Shag Point. In all these there are only four phalanges in the outer toe, so that this must be considered the normal number in the genus.
[Footnote] * Trans. N.Z. Inst., vol. xxv., p. 102.
Dinornis crassus, Owen.
Emeus crassus, Lydekker.
Syornis crassus, Hutton (not Palapteryx crassus, Haast).
The number of leg-bones measured was—metatarsi, 108; tibiæ, 99; femora, 101. This species, although so difficult to disentangle from M. casuarinus, is distinguished by its greater robustness, and by having a shorter tibia but longer femur. Here again the diagrams show only one point of concentration for each bone, so that there could not have been a difference in size between the sexes.
The width of the sternum below the costal border is about 5.8in., and the length of the body is 5in. The length of the pelvis is 16in. to 17.5in., and its width at the antitrochanters is 8.5in. to 9in.
Palapteryx elephantopus (part), Haast.
Emeus, sp. a, Lydekker.
Euryapteryx ponderosa and E. elephantopus (part), Hutton.
The number of leg-bones measured was—metatarsi, 25; tibiæ, 15; femora, 23. The width of the sternum below the costal border is 6in. to 6.5in., and the length of the body 4.5in. to 4.7in. The length of the pelvis is 18in. to 19in., and its width at the antitrochanters is 10.5in. to 11.5in.; the depth of the antacetabular part of the ilium is 5in. to 6in.
The diagrams show a single point of concentration in the metatarsi and tibiæ, but the femora are diffused. The leg-bones differ from those of E. crassa more in thickness than in length, but as a species it is well marked off, especially by its relatively longer and stouter tibia.
Dinornis gravis, Owen.
Euryapteryx gravis, Haast.
Emeus gravipes, Lydekker.
Euryapteryx gravis and E. compacta, Hutton.
The number of leg-bones measured was—metatarsi, 23; tibiæ, 12; femora, 16. The width of the sternum below the costal border is about 5in., and the length of the body 4in. The length of the pelvis is about 14.5in., and its width at the antitrochanters is 7in. to 8in.
In this species none of the bones show a decided concentration. It is very closely allied to E. crassa, the limb-bones having the same proportionate lengths, but it is smaller,
and the femur and metatarsus are proportionately stouter. Also, there is often a transverse depression on the anterior surface of the metatarsus at the base of the fourth trochlea, which seems to imply some peculiar habit.* The skull is shorter and flatter than that of E. crassa, and usually the temporal fossæ are deeper.
In the femur the head is moderate in length and the neck is well marked. The internal trochanterial surface is slightly concave. The shaft is slender, and slightly curved longitudinally on the anterior surface; the linea aspera indistinct. The popliteal depression is long, and very shallow; the two tuberosities are but slightly developed.
The length of the tibia is from 12 to 13 times its width in the middle. The shaft is straight, and the antero-outer surface slightly convex. The distal extremity is moderately expanded inward; the extensor bridge and tubercle are directed above the outer condyle.
The length of the metatarsus is from 5 to 6 times its width in the middle. The proximal articular surface has its inner margin flat or concave. The proximal interosteal foramina open separately on the anterior surface, or into a shallow depression. Usually the trochleæ do not diverge so strongly as in Megalapteryx, but this differs in different species. The second trochlea is not so long as in Meionornis, and its base is not so broad as in Megalapteryx. Usually there is a depression at the base of the anterior surface of the third trochlea, but this sometimes occurs also in Meionornis.
Anomalopteryx fortis, Hutton.
The bones belonging to this species were four metatarsi, two tibiæ, five femora, a sternum, and a pelvis. Of the metatarsi, the largest has a length of 8in. and a mid-width of 1.4in.; the smallest is 7.3in. long, with a mid-width of 1.3in. In both of them the proximal width was 2.3in., and the distal width 3in.
Of the tibiœ, the largest was 16.5in. in length, 1.3in. in width at the middle of the shaft, and 2.1in. at the distal end. The smallest was 15.8in. long, with a mid-width of 1.3in. and a distal width of 2in.
Of the femora, the largest was 10.2in. long and the smallest was 9.6in.; in both the mid-width was 1.3in. and the distal width 3.9in.
[Footnote] * This occurs also in Anomalopteryx fortis.
The sternum has distinct, but round and shallow, coracoidal pits, very different from those of A. parva. The width below the costal border is 3.7in., and the length of the body is 3.5in.
The pelvis has a length of 15.7in., and its width at the antitrochanters is 7.5in.; the depth of the pre-acetabular portion of the ilium is 3.7in. It is relatively broader than the pelvis of A. parva, but resembles it in other respects. From the pelvis of M. didinus it can be distinguished by the compressed centra of the pre-sacral vertebræ, and by the greater length of the mass of sacral vertebræ (numbers 35–37), which have no transverse processes.
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
As A. fortis is a species not mixed, either at Kapua or at Glenmark, with any other of the same genus, it will perhaps give us some idea of the amount of variation in size in the different species of moas. I find that the metatarsus varies about ⅛ in length and 1/7 in mid-width. The tibia varies ⅛ in length and 1/14 in mid-width. The femur varies 1/9 in length and 1/14 in mid-width. In the metatarsus both the distal and the proximal width vary about 1/6; but in the tibia and in the femur the distal width is the most constant element, the variation being only 1/20 and 1/17 respectively. It thus appears that the metatarsus is the most variable bone.
In the femur the head is rather short, the neck thick and but slightly constricted. The internal trochanterial surface is flat, or slightly concave. The transverse section of the shaft is usually oval, but it is variable. The linea aspera is broken and not well marked. The popliteal depression is short and deep; the two tuberosities are usually separated, and the inner one placed on the inner margin of the popliteal depression. The distal extremity is much expanded; the inter-condylar fossa nearly as deep on the outer as on the inner side. From the femur of Euryapteryx it may be distinguished by the shorter and thicker head, and by the internal trochanterial surface being flatter.
The length of the tibia is between 7 ¾ and 11 times that of the width of the shaft in the middle. The shaft is usually straight, but sometimes it is considerably curved inward; its antero-outer surface is usually convex (flat in P. immanis). The distal extremity is much expanded inward, and the distal width is almost always more than 3.3in. The extensor bridge and its tubercle are directed at the outer condyle.
The length of the metatarsus is from 3 to 4 ¼ times that of its mid-width, which is always greater than that of the tibia or femur. The proximal articular surface has the inner margin
sinuated. The proximal interosseous foramina either open separately on the anterior surface, or into a shallow depression situated above the insertion of the tibialis anticus, and there is no rough tubercle on the inner margin of this depression. The trochleæ are much expanded, and the third projects forward more than in any other species.
The differences between the species depend more on the thickness than on the length of the leg-bones.
Palapteryx elephantopus (part), Haast.
Dinornis elephantopus, var. major, Hutton.
Pachyornis immanis, Lydekker.
The number of leg-bones measured was—metatarsi, 18; tibiæ, 7; femora, 9. I cannot distinguish the sternum and pelvis of this species from those of P. elephantopus.
The diagrams show that, while the metatarsi are diffused, the tibiæ and femora tend slightly to concentrate on two points far apart. In the larger form the shaft of the tibia is much curved inwards, but it is nearly straight in the smaller form. This looks as if the species ought to be broken up into two, but the remains are too few to enable me to do so with confidence. In the metatarsus the proximal interosteal foramina always open separately on the anterior surface, and there is no depression above the insertion of the tibialis anticus; but this does not hold good for bones from other localities.
It is impossible to distinguish accurately between the metatarsi of this species and P. elephantopus, but the axial skeleton shows many differences.
Dinornis elephantopus, Owen.
Palapteryx elephantopus (part), Haast.
Pachyornis elephantopus, Lydekker.
Euryapteryx elephantopus (part), Hutton.
The number of leg-bones measured was—metatarsi, 37; tibiæ, 30; femora, 25. The width of the sternum below the costal border is 7in. to 8in. The pelvis has a length of about 20in., and its width at the antitrochanters is about 10.8in.
Concentration is fairly well marked in the metatarsi and femora, but not in the tibia, which is unusual. In the metatarsus the proximal foramina open either separately on the anterior surface, or sometimes into a depression. The shaft of the tibia is nearly always straight, and its antero-outer surface is convex.
Pachyornis, sp. a, Lydekker.
Pachyornis inhabilis and P. valgus, Hutton.
The number of leg-bones measured was—metatarsi, 8; tibiæ, 8; femora, 4. The sternum has a width of 6in. to 6.5in. below the costal border. The pelvis has a length of from 17in. to 20in., and its width at the antitrochanters is 9in. to 9.7in.
This species is more slender than P. elephantopus, and does not attain to so large a size; the skull also is different; but the two are closely connected. In the metatarsus the proximal interosteal foramina always open into a depression above the insertion of the tibialis anticus.
Harpagornis assimilis, Haast.—One tibia only.
Nestor, sp. ind.—One cranium, smaller than any living species.
Fulica prisca, Hamilton.—Two broken tibiæ.
Aptornis bulleri, Owen (Buller's “Birds of New Zealand,” Introduction, p. xxiii.).—A cranium, a pelvis, two femora, two tibiæ, a metatarsus, and two vertebræ, equal in size to A. defossor.
Notornis, sp.—One metatarsus.
Cnemiornis calcitrans, Owen.—A cranium and a pelvis.
Leg-Bones from Kapua.
|Length.||Proximal Width.||Middle Width.||Distal Width.||Length.||Proximal Width.||Middle Width.||Distal Width.||Length.||Proximal Width||Middle Width.||Distal Width.|
Leg-Bones from Kapura.
|—||Length.||Mid-width of Shaft in Inches.|
Leg-Bones from Kapua.
|Mid-width of Shaft in Inches.|
|Mid-width of Shaft in Inches.|