ANTARCTIC FISHES OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 333 



and New Zealand (Bovichthys variegatus), to New Zealand and South America 

 (Notothenia macrocephala, N. cornucola), or to the Antarctic Continent and Kerguelen 

 (Xotothenia coriiceps, Harpagifer bisjnnis) ; and if under the existing conditions 

 species may have this wide distribution, the fact that some are more restricted and are 

 separated from the most nearly related forms by wide expanses of ocean can be 

 explained without the theory of land-bridges. 



Many of the more southern types appear to be circumpolar ; for example, 

 Trematomus neivnesii, T. borchgrevinkii, T. bernacchii, T. hansoni, T. loennbergii, 

 Pleuragramma antarcticum, Notothenia coriiceps. 



With the exception of Pseudaphritis urvillii from the rivers of Tasmania and S.E. 

 Australia the Nototheniiform fishes are marine, and the great majority of them are 

 littoral ; several have been described as frequenting the rocks and weeds, but others 

 prefer deeper water, the species varying in this respect like the Cottids and Gobies of 

 our northern seas. Fishes pertaining to four genera (Bathydraco, Gerlachea, 

 Racovitzaia, Cryodraco) live in the open sea, and probably at some distance below 

 the surface. 



Most of the fishes of this group feed on crustaceans, molluscs, etc. (cf. LONNBERG, 

 Fish. Swedish South Polar Exped., p. 55), but Gymnodraco and the Chaenichthyidae 

 are no doubt piscivorous. According to LONNBERG (I.e., p. 52) the breeding season varies, 

 some species probably spawning in the spring, others in the summer, others in the 

 autumn. The eggs are smaller in Notothenia and Trematomus than in Artedidraco 

 and Champsocephalus ; they are probably demersal in all, but certainly in the last two 



genera. 



Synopsis of the Families. 



I. One radial on hypercoracoid, two on hypocoracoid ; gill-membranes separate, 



free from isthmus ; teeth on vomer and palatines ; mouth protractile ; snout 

 not produced ; a spinous dorsal fin . . . . 1. Bovichthyidse. 



II. All three radials on hypocoracoid ; gill-membranes united, free or attached to 



isthmus, usually forming a fold across it ; palate toothless. 



A. Palatine and pterygoids normally developed. 



Mouth protractile ; snout not produced ; a spinous dorsal fin 2. Nototheniidse. 

 Mouth not protractile ; snout produced ; no spinous dorsal fin. 



3. Bathydraeonidse. 



B. Palatine in great part ligamentous ; no mesopterygoid ; mouth not protractile ; 



snout produced and depressed .... 4. Chsenichthyidse. 



Family 1. BOVICHTHYIDSE. 



This family includes Nototheniiformes more generalised than the rest in the presence 

 of bands of cardiform or villiform teeth not only in the jaws, but on the vomer and 

 palatines, and in the separate free gill-membranes. All other members of the group 



(ROT. SOC. EDIJf. TRANS., VOL. XLIX., 251.) 



