14 



PROTOZOA. 



FIG. 9. Planorbulina (Acervu- 

 l ! it a) ylvbosa (after M. Schultze). 



Fam. 9. Lagenidae. Test calcareous, very finely perforated ; either mouo- 

 thalamous, or consisting of a number of chambers joined in a straight, curved, 



spiral, alternating or (rarely) branching series. 

 Aperture simple or radiate, terminal. No inter- 

 septal skeleton nor canal system. Layena Walker 

 and Boys, monothalamous ; Nodosaria Lamarck, 

 chambers in linear series ; Linyulina d'Orb., 

 Frondicularia Defrance, Rhabdogonium Reuss, 

 Marginulina d'Orb., Vaginulina d'Orb., Rimu- 

 lina d'Orb., Cristcllaria Lam., chambers in spiral 

 series ; A mphicorync Schlumberger, Lingulinopsis 

 Reuss, Flabellina d'Orb., Polymorphina d'Orb., 

 Dimorphina d'Orb., Uvigerina d'Orb. 



Fam. 10. Globigerinidse. Test free, calcareous 

 perforate ; chambers few, inflated, arranged spi- 

 rally ; aperture single or multiple, conspicuous. 



No supplementary skeleton nor canal system. All the larger species pelagic in 

 habit. Globiycrina d'Orb. when taken in a spoon shows very long fine calcareous 

 spines projecting from the shell (Fig. 10). These are not found in forms taken 

 in the tow-net or in ooze. Dimorphism has not been observed in this genus. 

 Orbulina d'Orb., spherical shell, often double, containing Globigerina-like shell ; 



it is formed by the external 

 protoplasm as a kind of 

 large last chamber. Hasti- 

 gerina Wy. Thomson, Pul- 

 Ui>in P. and J., Sphceroidina 

 d'Orb., Candcina d'Orb. 



Fam. 11. Rotalidae. Test 

 calcareous perforate ; free 

 or adherent. Typically 

 spiral and " Rotaliform," 

 i.e., coiled in such a man- 

 ner that the whole of the 

 segments are visible on the 

 superior surface, those of the 

 last convolution only on the 

 inferior or apertural side, 

 sometimes one face being 

 more convex, sometimes the 

 other. Aberrant forms evo- 

 lute, outspread, acervuline, 

 or irregular. Some of the 

 Fig. 10.HustigeriitH ((Hobigcrina) Murroyi W. Thomson, higher modifications with 

 bubbly vacuolated protoplasm, enclosing 6, the per- double chamber walls, sup- 

 forated Globigeriua.like shell. IFrom the peripheral p ] ementa l. skeleton, and a 

 protoplasm project not) only fine pseudopodia, but , , . .,, . 



hollow calcareous spines, which are set on the shell system of canals. Spinlhna 

 (from Murrayj . Ehrbg., Cymbalopora Hage- 



uow, Discorbina P. and J., 



Planorbulina d'O. (Fig. 9), Truncatulina d'O., Anomalina P. and J., Carpcn- 

 tcria Gray, Pulvinulina P. and J., liotalia Lam., Calcarina d'O., Tinoporus 

 Carpenter, Gypsina Carter, Thalamopora Roemer, Polytrema Risso, Patellina. 



