PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 353 



Color very dark sooty, almost black above, grayisb black below, with- 

 out spots or distinct markings. A very obscure grayish lateral streak. 

 Inside of upper lip blotched with black. Young specimen clear brown. 



This species is known to us from two specimens, the larger, a female 

 43 inches in length, the type of the i^resent description, having been 

 obtained by James G. Swan, assistant to the United States Fish Com- 

 mission, at Xeah Bay, near Cajie Flattery. The other was secured by 

 Mr. Gilbert at Soquel, on the Bay of Monterey. 



This species is closely related to Hexanchus griseus Raf. of the Medi- 

 terranean and Eastern Atlantic. It difl'ers chiefly in the form of the 

 teeth of the lower jaw, which are serrated on the inner edge, and have 

 on the upper or outer edge only six cusps instead of eight or nine. 



Another Notidanoid shark, belonging to the related genns Hepfran- 

 chias, distinguished by the presence of seven gill-openings instead of six, 

 is found with the i^resent species in the same waters. This is HeptrancMas 

 maculatus^ the N'otorhynchus macidatus or Notorliynchus horealis of Ayres 

 and Gill. This species differs from HeptrancMas indicus, with which it 

 has been confounded by Giinther and Dumeril, in the lack of a median 

 tooth in the upper jaw, and in the longer tail, which forms rather more 

 than a third of the total length. 



Heptranchias maculatus is rather comrhon on the coast of California from 

 Monterey northward. In Humboldt Bay it is especially abundant, and 

 the pursuit of it for the oil in its liver is an industry of some importance. 



The teeth in this species undergo some changes with age, and at least 

 are subject to some individual variations, as will be seen from the fol- 

 lowing descriptions, which may be comi)ared with Professor Gill's ac- 

 count of the jaws of Noforhynchus maculatns (Proc. Ac. Nat. Sci. Phila. 

 1862, 495) from Msqually, Washington Territor3\ 



Description of HeptrancMas macidatus^ juv., from Soquel. 



Head rather depressed, broad, rounded. The nostrils almost at the tip 

 of the snout. Length of the snout much less than the interorbital 

 width. Spiracle rather large, nearer the gill-oi)enings than the eye. A 

 long furrow at the angle of the mouth, above which the upper lij) ex- 

 tends backward in a broad fold. 



In the upper jaic no median tooth; two small teeth near together, 

 "well in front, simi)le and pointed ; two a little larger, behind and outside 

 of these ; then two more, similar, near together and directly within the 

 first pair ; then directly behind the second pair mentioned two much 

 larger ones, pointed, each with a conspicuous cusp on the outer edge 

 near the base on each side, and one or more denticnlations. The next 

 tooth is similar, rather larger and directed more outward. The remain- 

 ing five or six grow still more oblique, but are otherwise similar in form 

 and size, but a little more serrated. 



The median tooth in the lower jaw is broad, with two (or three) strong 

 dentations on each side, directed outward, and a very small median cusp 

 Proc. Nat. Mus. 80 23 ©ec. SI, 1 880. 



