682 REPORT—18638. 
Californian species. U. S. Atlantic species. 
Liocardium substriatum. L. Mortoni. 
Lunatia Lewisii. L. heros. 
Nacsa mendica. N. trivittata. 
Amycla (species). Amycla (species). 
126. When, however, we approach 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 
New England species in the West-coast fauna. As might be expected, tue 
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 is, 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, 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 Vancouver 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 Mammaliferous Crag. The fourth contains the species living in the 
British seas; the fifth, on the American side of the Atlantic, Gr. standing 
for Greenland. 
East Asia. West America. Crag. British. | E. America. 
K V__ Rhynconella psittacea ..| (Pleistocene) |psittacea _[psittacea 
— VC Xylotrya pennatifera.... —- pennatifera — 
— V_Xylotrya timbriata...... — fimbriata 
— VC Zirphea crispata ...... CRM _|{erispata __[crispata 
K VC Saxicaya pholadis ...... CRM _ |pholadis _ [pholadis 
J VC Glycimeris generosa ....| Faujasii, C R _- = 
— V_ Sphenia ovalis ........ ‘?Binghami’ f |Binghami — 
JK VY Mya ‘troncata.....5..... CRM _ {truncata _ |truncata 
JK, lata | V = Macoma inquinata...... lata, RM  |proxima roxima,&¢ 
K V__ Serripes Greenlandicus .. RM = reenland. 
K VI_ Venericardia borealis... . — — borealis 
— V_ Astarte (compacta) ....jcompressa,R M\compressa |compressa 
— V_ Miodon prolongatus ....| corbis, CR = — 
— IF Lucina borealis ........ CRM _ _/borealis — 
— I Cryptodon flexuosus .... C flexuosus — 
China |I _ Verticordia 9-costata....| cardiiformis,C} — — 
— VC Kellia suborbicularis . :. . CR suborbicul. _— 
* Whether there be any similar correspondence in the Polyzoa is not yet known, Mr. 
Busk not having had time to complete his examination. 
t See, in this connexion, a very accurate Table of the species which travel round 
Cape Cod, with their distribution in existing seas and over different provinces of the 
various drift-formations in the Old and New World, by Sanderson Smith, in Aun. Lye. 
Nat. Hist. N. York, vol. vii. 1860, p. 166. 
{ From the Coralline Crag. Looks more like ovalis. 
