682 



EEPORT ] 8C3. 



Culiforninn species. 



Liocaidium substriatunL 

 iiUiiatia Jiewisii. 

 Na.<sa mendica. 

 Amycla (species). 



U. S. Atlantic 



\j. Mortoni. 

 L. heros. 

 N. trivittata. 

 Amycla (species). 



^pene% 



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

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

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

 Isew England siiecies 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 diffuse themselves widely over the hemisphere. 

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

 Asia and West America which are not found in Grand Manau and Xew 

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

 Crag, as Acila, Miodon, Vertuordia, and Sidariella, 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 +, so widely diffused over Europe 

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

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

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

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

 Japan. In the second column, V signifies the Vancouver district, C the CaU- 

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

 are also fossil. In the third column, C denotes the Conilline, R the Hod, and 

 jr the Mammaliferous Crag. The fourth contains the species living in the 

 British seas ; the fifth, on the American side of the Atlantic, Gr. standinjj 

 for Greenland. 



* Wliether there be any similar correspondenee in the Polyzoa is not yet known, Mr. 

 Busk not '.laving had time to complete his examination. 



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

 Cape Cod, with their distribution in existing seas and over diHerent provinces of tli3 

 various drift- format ions in the Old and New World, by tiauderdou Jiuuth, in Axm. Lye, 

 Kdt. Hist. N. York, vol. vii. 18G0, p. lOti. 



% from the Curalliuc Crug. Looks more like ovalia, 



168 



