682 



EEPORT 1863. 



Californ'ian species. 

 Liocardium substriatum. 

 Lunatia Ijewisii. 

 Na?sa mendica. 

 Amyola (species). 



U. S. Atlantic species, 



L. Mortoni. 

 L. heros. 

 N. trivittata. 

 Amycla (species). 



126. When, however, we approacli the region in which boreal and sub- 

 boreal forms occur, many species are found in common, and between others 

 there is but slight difference. Yet even here there are more British than 

 l\ew England species in the West-coast fauna. As might be expected, the 

 British species are for the most part those which are also found fossil, and 

 therefore have had time to diifuse themselves widely over the hemisphere. 

 It ia, however, remarkable that many Crag species have reached Eastern 

 Asia and West America which are not found in Grand Manan and New 

 England. It is also extraordinary that certain special generic forms of the 

 Crag, as Acila, Miodon, Verticordia, and Solariella, reappear in the North 

 Pacific*. When seeking for an explanation of so remarkable a connexion 

 between faunas widely removed in space and time, the correlative fact must 

 be borne in mind, that the northern drift t, so widely diffused over Europe 

 and Eastern America, has not yet been traced in the western region. The 

 following Table exhibits, not only the identical but the similar species be- 

 longing to the northern faunas of the Atlantic and Pacific. In the Asiatic 

 column, K denotes that the species occurs in the Kamtschatka region, J in 

 Japan. In the second column, V signifies the Yancouver district, C the Cali- 

 fornian, and I the Sta.. Barbara group of islands. The species marked F 

 are also fossil. In the third column, C denotes the Coralline, R the Red, and 

 M the llammaliferous Crag. The fourth contains the species living in the 

 British seas ; the fifth, on the American side of the Atlantic, Cfr. standing 

 for Greenland. 



* Whether there be any similar correspondence in the Polyzoa is not yet known, Mr. 

 Busk not having had time to complete his e.xamination. 



t See, in this connexion, a very accurate Table of the species which travel round 

 Capo Cod, with their distribution in existing seas and over different provinces of the 

 various drift-formations in the Did and New World, by Sanderson Smith, in Ann Lv.-' 

 Nat. Hist. N. York, vol. vii. 1860, p. 166. 



J From the Coralline Crag. Looks more like ovalis. 



168 



