GLOBIGERINA LINNtEANA. 285 



Occurrence. — Globigerlna bulloides is a cosmopolitan species, found at all 

 depths. Its earliest recorded appearance is in the Devonian (Terquem, ' Bull. 

 Soc. G60I. France,' ser. 3, vol. viii, 1880, p. 418, pi. xi, figs. 10 a — c) ; it occurs in 

 the Jurassic (Terquem and Hausler) ; it is abundant in the Chalk-marl and Chalk ; 

 and it has been found in nearly all subsequent marine deposits. 



It forms an important constituent of the existing sea-bed wherever the depth 

 of water exceeds 100 fathoms. At smaller depths it is comparatively rare ; but 

 it abounds on some coasts, and chance specimens have been found in brackish 

 shallows, and even in the rivers of the Fen disti'icts of Lincolnshire at a distance 

 from the open sea. 



Olobigerina buUuides is one of the pelagic species collected by towing nets in 

 the open ocean, in company with two or three species of Pulvimdina. 



It seems that the Crag sea was not very favorable to the existence of this 

 species ; small specimens, however, are found throughout the Coralline Crag, 

 and in the Upper Crag of Southwold. 



2. Globigeeina Linn^ana (d'Orbigny), 1839. Plate VII, figs. 23 «, b, c. 



RosALiNA LiNN^ANA, d'Orb., 1839. Foram. Cuba, p. 101, pi. v, fige. 10 — 12. 



— CANALICCLATA, Reuss, 1854. Denksch. k. Ak. WIbs. Wien, toI. vii, 



p. 70, pi. xxvi, figs. 4 a, b. 

 Globigekina LiNif.SANA, Brady, 1884. Report ' Challenger,' p. 698, pi. Ixiiii, 



figs. 12 a, h : pl. exiv, figs. 21 a — c. 



— — Burrows, Sherborii, and Sailei/, 1890. Journ. R. Microsc. 



Soc, p. 561, pl. xi, fig. 19. 

 RoTALiA A8PEEA, Beissel (after Ehrenherg^), 1891. Abhandl. K. Preus. Landes., 



n. 8., pt. 3, p. 73, pl. xiv, figs. 1, 2. 

 Characters. — Rotaliform, compressed, slightly convex above, somewhat 

 concave with a sunken umbilicus below ; edge square and bicarinate, hence 

 canaliculate ; chambers numerous, strongly limbate ; apertures opening in the 

 umbilicus ; surface rough. 



Occurrence. — The only record of this species in the recent condition appears to 

 be that of the original from the shore-sands of the Island of Cuba. It is a 

 common Cretaceous fossil, but it does not appear to have been met with in later 

 deposits until we found specimens in the Coralline Crag of Sudbourne and Broom 

 Hill (both zone d). 



1 Beissel refers also to the ' Mikrogeologie,' pl. xxvii, figs. 57, 58, which occur among young 

 and adult forms of Ql. cretacea (figs. 53 — 59, and perhaps 60 — 64) (see ' Ann. Mag. Nat. Hist.,' 

 ser. 4, vol. ix, p. 294). These falsely appear to be marginate, owing to the translucent edges of the 

 chambers (seen by transmitted light), as is the case with many fisures in this and other plates. 



