Jordan and Evermann, Fishes of North America, 2535 



Gadus colinus, LACEPEDE, Hist. Nat. Poiss., n,41G, 1800, England, etc.; after LE COLIN of 



Danberton. 



Gadus viren.v, LACEPEDE, Hist. Nat. Poiss., u, 417, 1800. 



Merlangus 2)urpureus, MITCHILL, Trans. Lit. and Phil. Soc., 1, 1815, 370, New York. 

 Merlangus leptocephalus, DE KAY, New York Fauna: Fishes, 288, pi. 45, fig. 146, 1842, Long 



Island. 



Merlangus purpureus, STOKER, Kept. Fish. Mass., 130, 1839. 

 Pollachius carbonarius, GILL, Proc. Ac. Nat. Sci. Phila. 1863, 233. 



978. THERAGRA, Lucas, a new genus. 

 (ALASKAN POLLACKS.) 



Tlieragra, LUCAS, in Jordan & Gilbert, Kept. Fur Seal Invest. 1896 (1898) (chalcogrammus). 



This genus is closely allied to Pollachius, differing in the following 

 respects: Suboperculum thick, smooth and dense instead of being thin 

 and squamous as in Pollachius; the postclavicle is also similar in struc- 

 ture while its proximal portion is subcircular in Theragra and rhomboidal 

 in Pollachitts', this ivory-like character of the suboperculum and post- 

 clavicle is so marked that it serves to distinguish these bones at a glance, 

 being entirely different from what is found in the corresponding bones of 

 other gadoids. The Alaskan Pollack farther differs from the Atlantic Pol- 

 lack in having 19 precaudal vertebra? and 33 caudal, instead of 23 precau- 

 dals and 32 caudals ; the bodies of the vertebrae are also slightly longer 

 and more deeply sculptured in the Alaskan fish and the spinous process of 

 the anterior dorsals less elevated. The vertebral differences between the 

 2 genera are merely differences of degree and of specific value only, but 

 the differences between the subopercula and postclavicula are different 

 in kind, distinguishing the Alaskan Pollack not only from the Atlantic 

 Pollack, but from other gadoids. (Q 77/3, beast; ay pa, prey or food; the 

 Alaskan Pollack being a chief food of the fur seal, Callorhinus.) 



a. Dorsal rays about 13 or 14-17-18 or 19; anal rays 20-20; side with 2 interrupted dark 



longitudinal bands. CHALCOGRAMMA, 2904. 



aa. Dorsal ray a 10 or 11-13 to 15-16; anal rays 16 to 19-16 to 19 ; sides plain dusky; body 



less elongate, the snout blunter, the fins lower. FUCENSIS, 2905. 



2904. THERAGKA CHALCOGRAMMA (Pallas). 

 (ALASKA POLLACK.) 



Head 4; depth 6. D. 12-14-18; A. 20-20. Eye 5 in head; snout 3; 

 maxillary 2|; snout conic, sharp, rounded in profile; mouth oblique; 

 maxillary reaching middle of pupil; chin with a minute barbel; teeth 

 small, those, of the outer row above slightly enlarged; eye large, wider 

 than the flat interorbital space, 4 in head. Gill membranes somewhat 

 united, the posterior outline deeply emarginate; vent under interspace 

 between first and second dorsal; first dorsal higher than the others, the 

 second lowest; ventrals filamentous, reaching nearly to vent; pectorals 

 long, reaching past front of anal, 1| in head; caudal somewhat concave. 

 Olivaceous above, sides silvery, with 2 interrupted stripes of dark, brassy, 



