peduncle rounded above but flat below, and with a low dermal keel each side below the mid-level; the keels extend from just behind the posterior insertion of the 2nd dorsal base to about one-quarter of the distance along the caudal axis. A shallow upper precaudal pit is present, marking the origin of the epiural lobe; no lower precaudal pit.

Dermal denticles on sides of trunk somewhat spaced so that there are interspaces between them where the skin is exposed. In the 772 mm female they are mostly spearhead shaped, with a high median spine-like ridge, and a rhomboidal base; but in addition there are some larger denticles with tridentate blades. In the 935 mm female the denticles on the side of the trunk are nearly all of the tridentate form, and are more closely arranged, particularly on the posterior half of the trunk. Elsewhere on the body the denticles differ considerably in shape and sculpture, those from the caudal axis being less strongly tridentate and with a heavier median ridge; those from the interorbital region with heavy median and lateral ridges but no lateral teeth on the obtusely pointed blades, and those from the upper and lower lips almost sessile, the ridges lacking or reduced, and the blades obtusely pointed without lateral teeth.

Head measured to 1st gill-opening 6.5 to 6.6 in the total length. Head depressed and wedge-shaped in profile so that the snout tip is pointed. The least fleshy interorbital distance 2.3 in the head. Snout contour narrow and pointed, increasing smoothly in width to the level of the gill-openings. Length of snout measured to the eye 2.7 in the head. Eye longer than high, and 2.4 to 3.0 in the preoral length. Spiracle large and placed just above the dorsal margin of the eye and behind it by a distance equal to its own length. Gill-openings almost vertical, slightly concave, and in a horizontal series anterior to the pectoral base. Lengths of the gill-openings increasing slightly from the 1st to the 5th, the latter 1.2–1.3 in the horizontal diameter of the eye. Interspaces between the gill-openings subequal, though that between the 1st and 2nd is slightly greater than any of the others. Nostrils almost transverse and placed halfway between tip of snout and mouth. Interspace between nostrils 1.9 in snout measured to eye. Each nostril subdivided into a circular lateral aperture and an ovoid medial aperture by the anterior and posterior nasal flaps. The anterior nasal flap is triangular, directed posteriorly, and external to the fleshy posterior flap. The medial margin of the anterior nasal flap is smoothly concave in most specimens, but can have a minute lobe half-way along its length in others. Mouth broad and only slightly arched, its width 1.4 in the preoral distance. Preoral clefts short, reaching less than half the distance from the angles of the mouth to the upper symphysis; posteriorly the clefts are continued by oblique furrows which extend one-third of the distance between the angles of the mouth and the 1st gill-openings.

[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]

Teeth 12-14/11-12 in a 1,002 mm female, similar in the two jaws. Each tooth blade-like, with a base broader than high, and a single, smooth-edged, triangular cusp. The cusps are deeply notched on their lateral margins and so strongly oblique that their medial margins overlap from one tooth to the next and form a continuous cutting edge. The medial margins are slightly sinuous, especially towards the tips of the cusps which turn slightly downwards in the upper teeth, and slightly upwards in the lower teeth. In both the upper and lower jaws, the teeth at the centre of the mouth are distinctly smaller than those towards the corners; while in general the lower teeth are noticeably larger than the uppers. One or two lows of upper and lower teeth functional depending on the stage of replacement.

1st dorsal large, triangular, originating behind the level of the posterior corner of the pectoral fin by a distance not more than the horizontal diameter of the eye. The posterior insertion of the 1st dorsal base is midway between the levels of the axil of the pectoral and the origin of the pelvic in large specimens, but nearer to the origin of the pelvic in small specimens. Height of 1st dorsal equal to posterior part of its base measured from the origin of the spine, and also to the snout length measured to the eye. The 1st dorsal spine dusky-coloured, at least on its anterior surface, slightly curved, long and well exposed; its tip extending half-way up the anterior margin of the fin. Anterior and posterior margins of the 1st dorsal fin almost straight, distal margin concave and apex rounded. Length of posterior margin less than length of posterior part of base measured from origin of spine; posterior tip sharply pointed. The 2nd dorsal originating over posterior tips of the pelvics; smaller than the 1st and relatively more elongate, its height 1.7 in that of the first dorsal, and its base measured from origin of spine 1.5 in base of 1st dorsal. The distal margin strongly concave, and the posterior margin equal to or more than the length of base measured from origin of spine. 2nd dorsal spine dusky, longer than the 1st and reaching ⅔ or more of the distance to apex of fin. Caudal measured from hypural origin 5.0 in total length; epiural lobe well developed and without a subterminal notch, its upper margin almost straight, its lower margin smoothly curved, and the apex acutely rounded. Hypural lobe about half as long as the epiural, its anterior margin convex and its apex acutely rounded; angle between the posterior margin of the hypural and that of the epiural just more than a right angle and

smoothly rounded. Origin of the hypural just anterior to the epiural. Pectorals large and triangular, originating just behind the 5th gill-opening. The anterior pectoral margin smoothly convex, its length 1.7 to 2.0 times the width of the fin and just less than the distance from snout tip to 1st gill-opening; posterior margin almost straight, and distal margin distinctly concave. Anterior angle of the pectoral acutely rounded, the posterior angle just less than a right angle but smoothly rounded. Pelvics entirely anterior to the 2nd dorsal fin, shallowly triangular, their length of base about 1.5 times their height, and slightly more than the length of base of the 2nd dorsal measured from the origin of the spine. Anterior, posterior and distal margins straight, apex smoothly rounded and posterior tip sharply pointed.

Colour: Grey above, merging to brownish-white below. Two rows of white spots along the upper half of the trunk on each side, one row following the lateral line, the other nearer to the dorsal midline. Large specimens have fewer spots than small specimens, and occasionally lack them altogether. In most specimens, the lateral line row includes one spot anterior to the 1st gill-opening, two spots above the pectoral origin, one or two above the axil of the pectoral, and one to three beneath the 1st dorsal fin; behind the dorsal fin there may be further lateral line spots on juvenile specimens but they are not distinct in adults. The more dorsal row of spots includes one spot just in front of the 1st dorsal, one to four spots between the posterior tip of the 1st dorsal and the origin of the 2nd dorsal, and one or two spots between the posterior tip of the second dorsal and the origin of the caudal. In addition to the above, many specimens also have two white spots low down on the side of the trunk, one just above the 1st gill-opening, the other halfway along the base of the pectoral. In juvenile specimens the apices of the dorsal fins, and the tip of the caudal fin may be black.

Squalus blainvillii (Risso, 1826). Text-fig. 1, D-F; Text-fig. 3, A-F; Text-fig. 6, A-F

The first report of this species from New Zealand was by Regan (1914, p. 14) who recorded it as Squalus megalops (Macleay, 1882). Regan's record was based on a pregnant female taken in ten fathoms off North Cape, but apparently only the embryos were preserved. Through the courtesy of Dr. D. W. Tucker of the British Museum, I have been able to examine one of these embryos, a female 144 mm long with a large yolk-sac attached. The embryo shows the characters of S. blainvillii rather than S. megalops—i.e., the inner (posterior) pectoral corner is about a right angle, and is distinctly rounded. The identification is confirmed by the dermal denticles, for although these are only beginning to erupt on the skin from the side below the 1st dorsal fin, they are definitely tridentate as seen in a stained and cleared sample. This agrees only with S. blainvillii, for in S. megalops (and also in S. acanthias) the denticles of embryos and juveniles are dagger-shaped (Text-fig. 3).

Phillipps (1927, 1928) followed Regan in retaining the name of S. megalops, but later (1931, p. 360), on the basis of two specimens from the Hauraki Gulf, proposed this northern form as a new species, S. griffini. The description is meagre and comparison is made only with S. megalops of Australia. S. griffini is stated to differ from S. megalops by “the heavy, compressed, and unpolished appearance of the second dorsal spine,” and by having a somewhat shorter head and more rearward pelvic fins. I have examined the type of S. griffini (Dom. Mus. No. 662) and it is clearly not S. megalops, differing not only in the heavier dorsal spines, but also in having a rounded inner pectoral corner, and in the dermal denticles. It and other specimens from New Zealand that I have seen, are undoubtedly S. blainvillii, which, as I have pointed out in the introduction to this account, has been commonly but erroneously referred to S. fernandinus. S. blainvillii is a circumpolar species in both the northern and southern hemispheres, in tropical and subtropical waters as well as in the temperate region. My identification of it from New Zealand is based not only on the literature—Bigelow & Schroeder (1948, p. 456, fig. 87E) and Bigelow, Schroeder and Springer (1953, p. 220) give very good accounts of the species—but also on comparison with a specimen from the east coast of the United States of America, which was kindly sent by Mr. W. C. Schroeder, of Woods Hole Oceanographic Institution.