48G THE FUR SEALS OF THE PRIBILOF ISLANDS. 



This sijecies seems to differ from Gymnelis viridis in the more backward iusertion 

 of the dorsal, at least au eye's diameter behind the pectoral, and in the presence of a 

 large, jet-black ocellated spot on the dorsal over the vent. The small white spots 

 on anterior part of the body were apparently taken by Dr. Collie, its discoverer, for 

 "very small scales." The species is naked, and this discrepancy led Richardson to 

 redescribe this form as Oymnclis viridis var. unimaculaUis. Richardson's figures of 

 the two forms (Last Arctic Voyage) are excellent. Whether they are really distinct 

 remains to be proved. 



Family LYCODAPODID^E. 



201. Lycodapus exteusus Gilbert. 



From off Uualaska. 



202. Lycodapus parviceps Gilbert. 



From near Unalaska. 



Family GADID^^. 



203. Lota maculosa (Lo Suour). 



In the Yukon, Nushagak, and other rivers of northern Alaska. 



204. Theragra chalcogramma (I'allas). 



Unalaska, St. Paul, St. George, Bering Island, Petropaulski ; station 3G51, off 

 Kobben Reef, depth 20 fathoms. Everywhere abundant. The following notes are 

 from adult specimens: 



Olivaceous above, sides silvery, with two interrupted stripes of dark, brassy olive 

 along sides; these irregular on their edges, each about half width of eye; a trace of 

 a third similar stripe below anteriorly, the strii)es very irregular; back mottled 

 Dorsal plain dark olive; pectoral quite dark; lower fins ashy; caudal ashy olive. 



1). 12, 14, 18; A., 19, 20. Ventral nearly to vent; pectoral to anal, IJ in head; 

 eye 5; snout 3^; maxillary 24. Head 4; depth 6. 



The Alaskan i^llack seems to be tlie type of a distinct genus, for which Mr. Lucas 

 suggests the name of Theragra. The following is Mr. Lucas's note on the genus : 



The Alaskan pollack diH'era from tbe Atlantic pollack in having 19 precaudal and 33 caudal 

 vertebra' instead of 23 precandals and 32 caudals; tbe bodies of tbe vertebra; are also slightly longer 

 and more deeply sculptured in the Alaskan fish and the spinous process of the anterior dorsals less 



I'lfvated. 



The greatest diflerences between the two species, however, are to be fonnd in tbe gill covers, for 

 tbe suboperculum of tbe Alaskan pollack is thick, smooth, and dense, instead of. being thin .and 8(ina- 

 mous. The postclavicle is also similar in structure, while its proximal portion is snbcircujar in tbe 

 Alaskan species aud rhomboidal in tbe Atlantic. This ivory-like character of tbe suboperculnni and 

 ])Ost clavicle is so marked [in the Alaskan form] that it serves to distinguish these bones at a glance, 

 being entirely dififereut from what is found in the corresponding bones of other gadoids. 



°rhe vertebral differences between the two fishes are merely diflerences of degree and of specific 

 value only, but the differences between th(! eubopercula and postclavicula are differences in kind, 

 distinguisli'ing tbe Alaskan pollack not only from the Atlantic pollack, but from other gadoids. This 

 being'the cas'e, it is proposed to establish a distinct genus for the Alaskan pollack, and the name 

 Theragra is proposed for this genus. (F. A. L.) 



205. Gadus macrocephalus Tilesiua. Codfish. 



Everywhere common; taken at Karluk, Belkofski, Unga, Unalaska, St. Paul, St. 

 George, Bering Island. 



