Cope.] 24 [Jan. 17. 



A CONTRIBUTION TO THE ICHTHYOLOGY OF ALASKA. 



By Edward D. Coph, A. M. 

 (Read before the American Philosophical Society, January 17, 1873.) 



Prof. George Davidson of the United States Coast Survey, while en- 

 gaged in the prosecution of his duties off the coast of the Territory of 

 Alaska, made a collection of the species of fishes he observed at several 

 points. The principal localities where he collected were at Sitka and 

 Unalaska. The number of species is only sixteen, but they embrace an 

 unusual proportion of novelty, as the ichthyology of the region has been 

 but little examined. The additions to the science are of interest, and 

 such as to encourage the hope that the officers of the Survey will fre- 

 quently devote their attention to the natural history of regions to which 

 their dirties may call them. 



HOLOCEPHALI. 

 Hydrolagus collet, Bennet. 



Beachey's Voyage, p. 71 (Chimcera), Hydrolagus, Gill. 

 ISOSPONDYLI. 

 Salmo tudes. Cope, sp. nov. 



Group of Salvelini, i. e., with teeth on the anterior part only of the 

 vomer ; a median series of teeth on the postarior basihyal bones, and a 

 series on each side of the glossohyal. The vomerine teeth are small ; 

 those of the maxillaries, dentaries, and palatines are numerous and small. 



Form moderately stout, head quite small, conic, with wide frontal 

 region and small eye. Head five times in total length (including caudal 

 tin ); eye seven times in length of head, nearly three times in interorbital 

 width. Front nearly straight and descending in profile, convex trans- 

 versely, and with a weak carina, sometimes scarcely discoverable. Muz- 

 zle narrow, acuminate, slightly concave at the extremity to receive a 

 small knob-like projection of the symphysis of the mandible. Maxillary 

 bone narrow, extending a little beyond the line of the posterior margin 

 of the eye. Radii, Br. 11 ; D. I. 11 ; A. 10. Caudal fin openly forked ; 

 pectorals rather elongate, extending more than half-way to the basis of 

 the ventrals. Depth of body a little less than length of head. Scales : 

 1. 1. 119 ; those of lateral line larger than the other scales. Total length, 

 fourteen inches. 



Color steel-black above, yellow (in alcolipl) below the lateral line. 

 Rather numerous white (red?) spots about the size of the pupil of the 

 eye above the lateral line, arranged more or less quincuncially. They 

 also appear below the lateral line above the pectoral fin. Head black 

 above, sides bluish, fins unicolor. 



Two specimens from the island of Unalaska, taken at "Captain's 

 Harbor." 



This trout, or char, is allied to the species described by Pallas (Zoo- 

 graphia Rosso-Asiatica, vol. iii). from the eastern parts of Siberia and 

 the Kurile Islands. It is especially comparable to the Salmo leucomcenis 



