Genus Triacanthella Schaeffer.
Two further species of this genus have now been discovered in New Zealand, bringing the total number of species of Triacanthella known from the New Zealand region up to six. These may be separated according to the following key:—
|1. Ocelli eight on each side, of which none are rudimentary.||2|
|Ocelli eight on each side, of which two are reduced.||4|
|2. Claw without any teeth, clothing of strongly serrated setae.||T. setacea Salmon.|
|Claw with inner and outer teeth.||3|
|3. Clothing of simple setae; postantennal organ with four lobes, dens with apical scale-like lobe.||T. rubra Salmon.|
|Some of the setae serrated, postantennal organ with five lobes, dens without apical scale-like lobe.||T. purpurea sp. nov.|
|4. Empodial appendage absent, postantennal organ with four lobes.||T. rosea Wahlgren.|
|Empodial appendage present but rudimentary.||5|
|5. Claw without any inner teeth, a single distinctly clavate tenent hair to each foot, mucro with apical lobe and dens with apical scale-like lobe.||T. alba Carpenter.|
|Claw with two inner teeth, no clavate tenent hairs, dens without apical scale-like lobe.||T. terrasilvaticas sp. nov.|
Triacanthella setacea Salmon, 1941.
This species has now been found in leaf mould at Buller's Bush, Levin, by the author, thus extending its distribution to include the North Island as well as the South Island.
Triacanthella purpurea sp. nov. Pl. 40, figs. 1–5.
Colour: In life dark-reddish-violet to purple or dark-bluish violet, fading to light- or dark-red in spirit.
Clothing: Numerous long and short setae; the long setae particularly around the posterior portion of the abdomen about 3–4 times as long as the short setae. Many of the long setae are coarsely and irregularly serrated.
Body: Length up to 1.5 mm. Antennae shorter than the head. Ant. IV with three (sometimes four) exsertile knobs at the tip. On the dorso-lateral anterior extremity of Ant. III there is a sensory organ, consisting of two short curved sense rods, each arising from a shallow pit. Eight large equal ocelli to each side on clear fields, but each dark-pigmented in itself. Postantennal organ twice as long as an ocellus., with central boss, four peripheral lobes and one elevated lobe. Two long curved dorsal anal spines, each on a basal papilla about as long as itself. Below these there is a single smaller, slightly curved terminal spine mounted on a broad papilla. The terminal spine and papilla equal to half the anal spine and papilla in length. Cuticle coarsely granulate. Rami of tenaculum each with three teeth.
Legs: Claw with two inner teeth, one at about one-third and the other at a half down; and two outer lateral teeth, one to each side, at about halfway down from base. Empodial appendage rudimentary, but more developed than in T. rubra. A single faintly clavate tenent hair to each foot. This hair appears to be rather hooked than clavate. It is shorter than the claw.
Furcula: Manubrium short and stout, shorter than mucrodens. Mucro with blunt, curved apical tooth and sharper, taller pre-apical tooth connected to base by a broad lamella. Dens without apical scale-like lobe.
Localities: Titahi Bay, under driftwood and debris on the coast; Makara, under stones along the coast; Island Bay, Wellington, amongst rocks; (Author's Coll.); Red Rocks, Cook Strait, beaten from foliage (coll. by R. Forster).
Type: Slide 3/1188. Dominion Museum Collection.
Remarks: This species when found occurs in “nests” or clumps of individuals all tangled together. It is readily recognised in life by its distinctive dark colour.
Triacanthella terrasilvatica sp. nov. Plate 40, figs. 6–11.
Colour: In life pale-reddish-violet or pale-bluish-violet, fading to pale-pink or very pale-bluish-white in spirit.
Clothing: Numerous short and many relatively long serrated setae; those of Abds. V and VI may be as long as the depth of the segment. The degree of serration of the setae varies from slight on some individuals to very strong on others.
Body: Length up to 1.5 mm. Antennae slightly shorter than the head, the four segments related as 4:4:4:7. Ant. IV with two exsertile knobs at apex; Ant. III with sensory organ as in purpurea. Eight ocelli to each side, of which six are large and equal, and the remaining two, the posterior inner two, very slightly reduced in size. Postantennal organ with central boss and four peripheral lobes, the whole slightly larger than anterior ocellus. Rami of tenaculum each with three teeth. Cuticle coarsely granulate. A pair of large curved dorsal anal spines, equal to the hind claw in length, and a single shorter terminal anal spine below these. All mounted on papillae, the dorsal papillae four-fifths the length of their respective spines, the papilla of the terminal spine equalling the spine in length. All these anal spines are curved and relatively longer than the spines of T. rubra.
Legs: Claw with two inner teeth, one at one-quarter and the other halfway down from base. Two strong outer teeth, one to each side, at about one-fifth back from apex of claw. No tenent hairs.
Furcula: Mucrodens only slightly longer than manubrium. Dens with one exceptionally long basal seta and several smaller ones. Mucro as in the preceding species, but with apical tooth not quite so strongly curved and pre-apical tooth broader.
Locality: Johnson's Hill, Karori, in damp bush soil just below the layer of leaf mould in the bush. Occurs as single individuals and not very easy to detect. (Author's Coll.) Masterton on surface of puddles in concrete path, in vast numbers. (Coll. by Miss I. Tankersley.)
Type: Slide 3/1239, Dominion Museum Collection.