34 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
Family XV.— HEXANCHID^. 
{The Coic Sharl{s.) 
Body elougated, somewhat depressed anteriorly, tapering towards the 
caudal ftn. Head depressed, oblong and semi-oval or semi-elliptical 
above, with the snout projecting. Eyes snbmedian or anterior, without 
nictitating membranes. Month inferior, large, arched in front, no labial 
fold. Teeth in the two jaws unlike ; in the upi^er jaw one or two pairs 
of a wl-shaped teeth, the next six teeth broader, and each i)rovided ’with 
several cusps, one of which is much the strongest. Lower jaw with six 
large comb-like teeth on each side, besides the smaller posterior teeth. 
Spiracles small, on the side of the neck. 07i ly one dormljin, withou t spine, 
opposite the anal, and similar to it. No pit at the root of the caudal fin. 
Gill-openings wide, six or seven in number. Genera 2 ; species 4 or 
more; mostly ol’the Eastern Atlantic. {Notidanidw Giiiither, viii, 397- 
399.) 
* Gill-opeiiing!5 seven on each side Hcptancus, 32. 
32.— HEPTANCUS Ratinosque, IHIO. 
Perlons. 
CNotidanus Cuvier, 1817.) 
{HeptrancMas Ratinesqne, Caratteri di Alcuni Nuovi Generi, etc.: type Squalus 
cinereus Gmelin.) 
Characters same as those of the family with the addition of gill-open- 
hiffs seven, which separates this genus from Hexancus. (i-rd, seven; 
a/xo^, bend or sinus, for gill -opening.) 
* Median tooth of lower jaw without central cnsp. (Notorhi/nchus AyreH.) 
42. H. indiciis (Cuvier) Miiller & Henle. 
“ Snout short and rounded ; cleft of the mouth broader than long. A 
single nledian pointed tooth in the upi)er jaw; the lower median tooth 
with lateral cusps, but without central cusp. The first cusp of the lower 
teeth is much stronger than the others and serrated on its outer margin.” — 
(Giinther.) Dark bluish gray, with many small irregular black blotches. 
Tail mor(‘ than one third of total length. Size large. Cape of Good 
Hope to California:; not rare at San Francisco. 
(Aotidanus indicus Cnvier, Rcgnc Aninial: A^olidannn itidicus Giinther, viii, 398: Koto- 
rhynchus mHcvlo.tus Ayres, Proc. Cal. Nat. Sci. i, 72: Notorhynchus maculatus Gill, Proc. 
Ac. Nat. Sci. Phila., 1862, 495, and 1864, 149 : Notorhynchus borealis Gill, Proc. Ac. Nat. 
Sci. Phila. 1864, 150. 
