462 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



27. COELORHYNCHUS NOTATUS Smith and Radcliffe. 



Coelorhynchus notatus Smith and Radcliffe, Proc. U. S. Nat. Mus., vol. 

 48, 1912, p. 13G (type-specimen only), pi. 30, fig. 3. 



For the purpose of presenting a full comparison with the several 

 closely related species which we are now describing, we have prepared 

 a detailed description of this species. 



Type-specimen. — Cat. No. 72948, U.S.N.M.. is the only repre- 

 sentative of this species in the collection. It is a mature female, 

 measuring 268 mm. in total length to the broken tip of the tail, and 

 84 mm. to the center of the anus. These measurements indicate that 

 C. notatus is probably a larger species than any of the closely related 

 forms with the exception of C. velifer. The type was dredged at 

 Albatross station 5162, in Alice Channel, which connects Sulu Sea 

 with Celebes Sea; depth, 230 fathoms; bottom temperature, 52.9° F. 



Dorsal rays, II, 9; pectoral, 17 (including the uppermost spine) ; 

 ventral, 7. 



Greatest depth of the body, 1.7 in head ; width over pectoral bases, 

 2.25 in head, less than the depth below the origin of the lateral line. 

 The concavity of the dorsal contour of the snout is well shown in the 

 type figure ; the lateral margins of the snout are much less strongly 

 convex than in macidatus or velifer; they converge rather rapidly 

 forward. The tip of the snout is sharper than in G. maculatus or 

 veMfer, but somewhat blunter than in the other closely related 

 species: the snout near its tip is wider than deep; the terminal plate 

 projects but little beyond the general contour of the snout. The 

 preocular length of the snout is contained 2.71 times in the length 

 of the head (63 mm.) ; the preoral length, 3.00 times: width of snout 

 opposite front of orbits, 2.70 times. The posteroventral angle of 

 the subopercle is produced backward as a rather bluntly pointed flap. 

 Length of the orbit, 3.40 in head, 1.15 in postorbital length of the 

 head, 1.28 in snout. The least interorbital width, above the front of 

 the pupils, is contained 1.75 times in the postorbital; least sub- 

 orbital width, 2.60 times. The length of the upper jaw is contained 

 3.75 times in the head ; the maxillary subtends the anterior two-thirds 

 of the orbital length. The outer premaxillary series of teeth is 

 scarcely enlarged. Length of the barbel, 3.40 in postorbital. Branch- 

 iostegal rays, 6. A narrow free fold is formed on the median line 

 behind the attachment of the gill-membranes. 



The anus is remote from the anal fin, the interspace being con- 

 tained 1.6 times in the distance from the anus to the base of the outer 

 ventral ray, a distance which is slightly shorter than the orbit. The 

 interval between the isthmus and the base of the ventral fin is con- 

 tained 1.07 times in the postorbital, and is 1.1 times as long as the 

 distance from the ventral base to the isthmus. 



