TEMPERATE NOETH ATLANTIC. 267 



this district; and from the frequent occurrence of isolated 

 specimens of other British species on the North American 

 coast, we may presume that many more occasionally cross the 

 Atlantic, but without being able to obtain a permanent 

 footing. 



The genera peculiar to this district are few in number, 

 and composed of very few species, viz. Hemitripterus, Pam- 

 melas, Chasmodes, Cryptacanthodes, and Tautoga. 



The close resemblance of what must be considered 

 northern forms to those of Europe will be evident from the 

 following list : — 



Mustelus, Rhina, Torpedo, Raja, Trygon. 



Lahrax, Centropristis, Serranus ; Pagrus, Chrysophrys ; 

 Sebastes, Hemitripterus; Cottus, Aspidophoroides ; Uranosco- 

 pus ; Micropogon, Pogonias, Scicuna ; TracJiurus, Pammelas ; 

 Cyclopterus, Liparis ; LopJiius ; Anarrhicha^, Chasmodes, 

 Sticlioius, Ccntronotus, Cryptacanthodes, Zoarces. . 



Tautoga, Ctenolabrus. 



Gadus, Merluccius, Phycis, Molva, Motclla, Brosmius ; 

 Ophidium (one species, perhaps identical with a Mediterranean 

 species) ; Ammodytes ; Hippoglossus, Hippoglossoides, Rhombus, 

 Pleuronectes. 



Osmerus, Mallotus ; Engraulis, Clupea ; Conger. 



Syngnathus — Myxine — Branchiostoma. 



West Indian genera, or at least genera which are more 

 developed within the tropics, and which extend more or less 

 northwards in the North American district, are : — 



Pteroplatea (also in the Mediterranean). 



Gerres, Dules {auriga), Ldbotes, Ephifpus ; Sargus ; Priono- 

 tus ; Umbrina, Otolithus, Larirrms ; Sphyrmna (Mediterr.) ; 

 Trichiurus (Mediterr.); Elacate; Cybium, Trachynotus; Stro- 

 mateus (Mediterr.) ; Caranx ; Batrachus (Mediterr.) ; Malthc. 



Pscudorhombits, Solea (Mediterr.) 



Saurus (Mediterr.); Etrumeus, Albula, Elops, Megalops. 



