tlie Nomenclature of the Foraminifera. 295 



2)htna. No. 47, Uvigerina tricarinata, is one of the Textila- 

 riau Foraminifera that has not only departed from the common 

 type, and become three-sided {Verneuilina) ^ but has taken on 

 a pouting form of aperture (in this resembling Uvigerina) : 

 thus it lays claim to a distinct subgeneric name, and has been 

 called Tritaxia by Reuss. Nos. 46-42, Bidiinin(R : these, 

 being rough and somewhat sandy, are grouped under Ataxo- 

 phragmium by Keuss. Nos. 39, 38, 37, 34, 33, 32, 31, & 30, 

 grouped as Truncatulina, Rosalina., and Botalina^ are more or 

 less characteristic forms of the subfamily RotaUnce (Carpenter) , 

 and may be thus grouped : — 



Planorbulina Voltziana (30, Rotalina)^ belonging to the same 



group as PI. Icalemhergensis (D'Orb.). 

 Lorneiana {S8,RosaIina), belonging to the same group 



as FI. ammonoides (Rss.), and FI. hadenensis (D'Orb.), 

 Clementiana (39, Rosalina), an ornate variety of FI. 



tuherosa (F. & M. 



(subgen. Truncatulina) Beaumontiana (37, Truncatu- 



lina), merely a thick convex Tr. Johatida (W. & J.). 



Pulvinulina Micheliniana (31, i?oto//na), 1 See above, 



crassa (33, Rotalina). J p. 294. 



Cordieriana {^A^ Rotalina) . Feebler than F. Miche- 

 liniana. 



Rotalia umbilicata (32, Rotalina). Of the same group as 

 R. Soldanii and R. orhicidaris ; and not only existing in 

 the Adriatic, as stated by D'Orbigny, but found fossil in 

 the Tertiary beds of Italy. 



We can now-a-days indicate many more living analogues, 

 and, indeed, identical representatives, of the Chalk Foramini- 

 fera than M. D'Orbigny recognized in 1840 ; and we believe 

 he was wrong in supposing that Frondicularice, like those of 

 the Chalk live in the Adriatic*. Doubtless, however, he was 

 quite correct in saying that the sea in which the Chalk was 

 formed continued from western Europe into the English area, 

 was of a warm climate, free from shore-currents, and contained 

 species of Foraminifera that have lived on to the present day. 

 We may well add : — that it was of very great extent and of 

 considerable depth, though not so deep as our Atlantic ; that 

 some uninterrupted water-areas have continued its oceanic 

 existence, under various and great modifications, to the pre- 

 sent day ; that the Foraminiferal species which have per- 

 sisted in its depths throughout the enormous time required for 

 such changes of land and sea, were not uniformly represented 



* He seems to have met with some derived fossil forms in the sea-sand. 



