356 ADDENDA. 



keel -like crest; (posterior vomerine teeth sometimes 

 deciduous) ; species of various habit, black-spotted, the last 

 rays of the dorsal and anal somewhat elongate. SALMO, 2. 



ft Vomer somewhat boat-shaped, the shaft depressed and the 

 teeth placed not directly on the shaft but on a raised crest, 

 which is posteriorly free; a band of stout recurved 

 teeth on the hyoid bone; scales small; caudal well 

 forked ; dorsal and anal not elevated behind ; species of 

 large size, gray-spotted, not anadromous, inhabiting 

 American lakes CRISTTVOMER, 3. 



ftf Vomer somewhat boat-shaped; the shaft depressed and 

 entirely toothless; scales very small, in 225 250 rows; 

 dorsal and anal not elevated behind ; species of rather 

 small size, crimson-spotted, the lower fins with marginal 

 bands of black and pale; not anadromous, but some- 

 times descending to the sea, in salt water losing all 

 markings and becoming nearly plain silvery. 



SALVELINUS, 4. 



In the following account, I include all the species thus 

 far known from the waters of the United States, as the 

 general interest felt in this group of fishes seems to 

 render this arrangement desirable. 



/. ONCORHYNCHUS, Suckley. HOOKED- JAW SALMONS. 



* Body not greatly compressed; upper jaw the longer; sexual 

 peculiarities excessively developed; size large. (Oncorhyn- 

 chus.) 



. 0. gorbuscha, (Walbaum) Gill & Jordan. HUMP- 

 BACK SALMON. Scales very small, in more than 200 

 transverse rows. N. W. Coast. (S. proteus, Pallas. 

 S. gibber, Bloch.) 



2. 0. keta, (Walb.) G. & J. EKEWAN. Scales 

 medium, in 170 (155180) rows; B. 16. N. W. Coast. 

 (S. scouleri, Rich., /S. lagocephalus^ Pall., S. confluentus, 

 Suckl.) 



