358 TRANSACTIONS OF THE AMERICAN PHILOSOPHICAL SOCIETY 



though falling by definition with the percoid series would, I think, make an ideal starting- 

 point for those of Cottoperca, chiefly by the enlargement of the scapular foramen and the 

 fusion of the first actinost with the glenoid process of the scapula. 



Percis nebulosa.-Thh skull (No. 277, Brit. Mus. Nat. Hist.) (Fig. 2365) agrees m 

 essentials with that of Pinguipes but is longer. 



Eleginops maclovinus 



Fig. 238. Eleginops. 



Eleginops. —Th\s form (Fig. 238) differs from the typical notothenes in its small strong 

 jaws. The opercular series is remarkably large but at the same time more or less resemblmg 



both Pinguipes and Notothenia. s , , ,., , 



•Bathymaster signatus.—TKis skull (No. 287, Brit. Mus. Nat. Hist.) looks like a large- 

 mouthed pinguipid, especially in the palatal aspect. The premaxillae have normal ascendmg 

 processes but rather short alveolar borders, exposing the narrow maxilla in the lower half 

 of the gape. The suborbitals are thin, the lacrymal small and delicate, the nasal fossa 

 large The interorbital bridge is narrow, the eyes being large and directed upward; cranial 

 roof smooth, without crests. The opercular is small and percoid, the subopercular large 

 and forked, as in Leptoscopus. The preopercular is very narrow and reduced, but folded 

 around the lateral line canal. The pectoral girdle, including the pterygials, is of percoid 

 type, and this fish is referred to the Percoidea by Tate Regan. 



Notothenioids.— The most primitive genera of this diversified Antarctic group, according 

 to Tate Regan (1914), are the two genera of the Bovichthyidse, Cottoperca and Bovichthys. 

 Regan (1913a, p. 112) treats the group as a whole as a division, Nototheniiformes, of the 



Percomorphi. . u b • 



Cottoperca and Bovichthys.— SkuWs of these Interesting forms were examined m the Brit- 

 ish Museum (Natural History). In Cottoperca gobis (No. 278) the skull (Fig. 239^) m essen- 

 tial features strongly resembles the Pinguipes type described above (p. 3 56) . The Bovichthys 

 skull (No. 285) is very close to that of Cottoperca, with the important exception^ that the 

 opercular (Fig. 240C) has acquired a very large spine and a broad process from its dorsal 

 edge, articulating with both the pterotic and the lateral surface of the stout posttemporal. 

 The lower part of the opercular is reduced to a point which fits into a notch in the suboper- 

 cular. The very close resemblance in other features of Bovichthys to Cottoperca indicates 



