34 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



Family XV.— HEXANCHID^. 



{The Coiv SharU.) 



Body elongated, somewliat depressed anteriorly, tapering towards the 

 caudal tin. Head depressed, oblong and semi-oval or semi-elliptical 

 above, with the snout projecting. Eyes submedian or anterior, without 

 nictitating membranes. Mouth inferior, large, arched in front, no labial 

 fold. Teeth in the two jaws unlike ; in the upper jaw one or two jjairs 

 of awl-shaped teeth, the next six teeth broader, and each provided 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. Only one dorsal fin, nntliout spine, 

 opposite the anal, and similar to it. No pit at the root of the caudal tin. 

 Gill-openings wide, six or seven in number. Genera 2 ; species 4 or 

 more; mostly ol'the Eastern Atlantic. {Notidanidce Glinther, viii, 397- 

 399.) 



* Gill -openings seven on each side Heptancus, 32. 



32.— HEPTANCUS Katiues(iue, 1810. 



Ferlons. 



LNotidanus Cuvier, 1817. ) 



(Heptranchias Rafiuesque, Caratteri di Alcuui Nuovi Geueri, etc. : type Squalus 

 cinereus Gmeliu. ) 



Characters same as those of the family with the addition of gill-open- 

 ings seven, which separates this genus from Hexanms. {k-za, seven; 

 ay/.o'-,, bend or sinus, for gill -opening.) 



* Median tooth of lower jaw without central cusp. (Notorhijvchus Ayres.) 



42. H. indicilS (Cuvier) Mliller & Henle. 



" Snout short and rounded ; cleft of the mouth broader than long. A 

 single median pointed tooth in the upper 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." — 

 {OUnther.) Dark bluish gray, with many small irregular black blotches. 

 Tail more than one third of total length. Size large. Cape of Good 

 Hope to California ; not rare at San Francisco. 



(NotUkinus indicus CviyiiiT, Regue Animal: XoUdanusindicns Giiuther, viii, 398: Xoto- 

 rhynchus macvlolus Ayros, Proc. Cal. Nat. Sei. i, 72 : Noturhynchiis maculatns Gill, Proc. 

 Ac. Nat. Sfi. Phila.. 18ti2, 49.'), aud 1864, 149 : Notorliynchus horeall's Gill, Proc. Ac. Nat. 

 Sci. Phila. 1864. 150. 



