DISTRIBUTION OF SHORE FISHES. 293 



Shore Fishes. The fishes of the first category number upwards 

 of three thousand five hundred species. Their range in the north 

 extends to, or beyond, the eighty-third parallel of latitude, but in 

 the Southern Hemisphere no species have been found to pass be- 

 yond the sixtieth parallel, although, doubtless, they exist along 

 some of the more southerly shore-lines. The Arctic fauna, or the 

 fauna occurring north of the sixtieth parallel of latitude, is, as far 

 as we are warranted in believing, a strictly homogeneous one, iden- 

 tical types largely characterising both the Old and the New World 

 divisions. The more extensively represented families are, among 

 the spiny-rayed fishes, the bull-heads (Cottida3 Cottus, Icelus, Tri- 

 glops), the Agonida3, lump-suckers (Discoboli), and blennies (Blen- 

 niidae Anarrichas, wolf -fish) ; and among the anacanths the cod- 

 fishes, with the cod (Gadus), hake (Merlucius), arid ling (Molva). 

 Among the physostomous fishes, or those in which the air-bladder 

 is provided with a pneumatic duct, the herring (Clupea) is repre- 

 sented by a limited number of species. The cartilaginous fishes 

 are very scarce ; indeed, thus far only one species, the Greenland 

 shark (LaBmargus), is known to penetrate north of the Arctic cir- 

 cle. The chimera, spiny dog-fish (Acanthias), and ray, are met 

 with along the southern borders of this tract. 



The Antarctic shore fauna is in many respects closely related to 

 the Arctic, although nearly one-third of the generic types are 

 peculiar. As in the north, the cartilaginous fishes are scarce, 

 being represented by a single species of shark (Acanthias), and one 

 or more species of ray (Raja, Psammobatis). The Scorpa3nida3 and 

 Agonidai among bony-fishes have each one genus, Sebastes and 

 Agonus respectively, which is held in common with the Arctic 

 fauna. The lophobranchs have in addition to the northern pipe- 

 fish (Syngnathus) the remarkable Protocampus, represented by a 

 single species of the Falkland Islands (P. hymenolomus). A most 

 interesting fact connected with the Antarctic fauna is the recur- 

 rence of types belonging to the far north, which are wanting in 

 the intermediate region. This we see in the single species of 

 spiny dog-fish (Acanthias vulgaris), which is a member of the 

 Arctic and north temperate faunas, but is absent from the equa- 

 torial- region. The hakes comprise two species, one of which is 

 restricted to the northern waters and the other to the southern; 

 and a similar separation is found among the species of the Arctic 



