174 FORAMINIFERA OF THE CRAG. 



Cassidulina crassa, BiitscMi, 1880. In Bronn's Klass. Thier-Reichs, p. 205, 



pi. viii, fig. 6. 



— — Terrigi, 1883. Atti Accad. Pont. N. Lincei, vol. xxxv, 



p. 192, pi. iii, fig. 34. 



— ■ — Brady, 1884. Eeport ' Challenger,' p. 429, pi. liv, figs. 4, 5. 



— — Andreae, 1884. Abhandl. geol. Specialk. Elsass-Lothringen, 



vol. ii, part 3, p. 235, pi. x, figs. 31, 32. 



— — Egger,\9Qi. Abhandl. Bayer. A kad. "Wiss., vol. xviii, part 2, 



pp. 276, 308, pi. vii, figs. 35, 36. 



— OBLONGA, Idem. Ibid., figs. 33, 34. 



— CEASSA, Goes, 1894. K. Svensk. Vet.-Akad. Handl., vol. xxv, No. 9, 



p. 43, pi. viii, figs. 421, 422. 



Figs. 18 a, b. Cassidulina crassa, d'Orb. x 24. Prom the ' Phil. Ti-aDs.,' vol. civ, 

 pi. XV, figs. 6 and 7. 



Characters. — Shell ovate-oblong, biconvex, but more or less compressed; 

 margin obtuse or rounded. It is smaller and relatively thicker than Cassidulina 

 laevigata, and the segments are fewer and comparatively short and inflated. 



C. crassa, var. ohlonga (PI. IV, fig. 16), is an asymmetrical varietal modification 

 usually smaller than the type ; it indicates a possible line of divergence, but 

 not of much zoological importance. Dr. Egger (whose work in 1893 on the 

 Foraminifera collected by the ' Glazelle ' is referred to above) does not agree with 

 this amalgamation of the Cassiduline varieties (p. 303). 



Occurrence. — Cassidulina crassa has a world-wide range, and has been recorded 

 from depths ranging from 40 fathoms in the North Pacific down to 2760 fathoms 

 in the North Atlantic. 



The earliest recorded appearance of the species in a fossil condition is in the 

 Miocene of Vienna. It has been found in the Pliocene of Italy and St. Brth ; 

 and we have in our own Collection specimens from the Casterlian and Scaldisian 

 of Antwerp. So far as the Crag is concerned, we have nothing to add to the 

 record given in the First Part of the Monograph. 



Cassidulina ohlonga. — This variety appears only to have been met with in a 

 fossil condition. The formations in which it has been found are the Oligocene of 

 Elsass, the Miocene of Vienna, and the Pliocene of Garrucha (South Spain) and 

 St. Brth. So far as the Crag is concerned, we have nothing to add to the record 

 in the First Part of the Monograph. 



