60 ItAiftJAL OF THE MOLLFSCi. 



II. Boreal Peoyii^ce. 



The Boreal Province extends across tlie Atlantic from Nova 

 Scotia and Massachusetts to Iceland, the Faeroe and Shetland 

 Islands, and along the coast of Norway from North Cape to the 

 Naze. 



Of the 289 Scandinavian shells catalogued by Dr. Loven,* 

 217, or 75 per cent, are common to Britain, and 137 range as 

 far as the North coast of Sjoain. 



The boreal shells of America are described by Dr. Gould, f 

 From these lists it ajopears that out of 270 sea-shells found on 

 the coast of Massachusetts north of Cape Cod, more than half 

 are common to Northern Europe. 



Many of the species, it is believed, could only have extended 

 their range so distantly by means of continuous lines of con- 

 necting coast, now no longer in existence. | 



BOREAL SHELLS COMMOIS" TO EUROPE AIH) NORTH AJIERICA. 



* British Species. 



*Lucina borealis. 

 ? „ divaricata. 



♦Crj'^jtodon flexuosus. 

 *Astarte borealis. 



* „ triangularis? (quadrans, G-.) 

 *C}T)rina Islandica. 

 ? (Cardium Tslandicum, U.S.— N. Zerala). 



Yoldia limatula. 



„ arctica, Gr. (= mj-alis). 

 *Leda pygmsea. 



* „ caudata. 



? „ naviciilaris (lucida, Loven?) 

 *Nucula tenuis. 

 *MytiIus edulis. 

 *Modiola modiolus. 



*Teredo navali?. 

 •Pholas crispata. 

 *Solcn ensid. 

 *(Panop£ea) Nor\'egica. 

 *Mya arenaria. 



* „ truncata. 



*T]iracia phaseolina (Conradi, Couth). 



IMactra ponderosa (ovalis, G.) 

 ? ISrontacuta bidentata. 

 *Turtonia minuta. 

 PKellia rubra. 



P Lepton nitidura (fabagella, Conr. ?) 

 *Saxicava rugosa (arctica). 



Tellina solidula, var. (fusca, Say). 



* „ calcarea (sordida, Couth). 



* Index Molluscorum Scandinavia ; extracted from the " Ofversigt af K. Vet. 

 Akad. Forh." 1S16. The climate of Finmark is much less severe than Russian Lap- 

 land ; Hammerfost has an open harbour all tlie year. 



t Report on the Invertebrata of Massachusetts. 1?41. 



t Forbes, Memoirs of the Geol. Survey, i. p. 379. Sir John Richardson, -when 

 speaking of th* cod-tribe and turbot-tribe, sas^s:— "Most of the fish of this order feed 

 on or near the bottom, and a veiy considerable number of the species are common to 

 both sides of the Atlantic, particularly in the higher latitudes, -n-here they abound. It 

 does not appear that their general diffusion ought to be attributed to migration from 

 tlieir native haunts, but rather that in this respect they are analogous to the owls, 

 which, though mostly stationary birds, yet include a greater proportion of species 

 common to tlie old and new worlds than even the most migratory families. Several of 

 the Scomber oidece (Mackerel-tribe) which feed on the surface, have been previously 

 noted as traversing many degrees of longitude in the Atlantic: but the existence of 

 the ground-feeding Gadoidece in very distant localities must be attributed to a different 

 cause, as it is not probable that any of them wander out of soundings or ever approach 

 the mid-seas."— Report Zool. N. America, p. 218, 



