LITERATURE OF THE FORAMINIFERA 147 



their alar prolongations enclosing the previous whorls ; a complex canal 

 system. (Figs. 5 and 6.) Assilina, d'Orb. Complanate, structure as in 

 Nummulites, but the alar prolongation of the chambers are thin, so that 

 the outline of the inner convolutions is visible. Heterostegina, d'Orb. 

 Resembles Operculina in plan, but the chambers subdivided into chamber- 

 lets, and equitant. (Fig. 56.) Cycloclypeus, Carp. Chambers usually in a 

 single layer, confined to the median plane of the test ; at first spiral, 

 then cyclical (Figs. 57 and 58). Orbitoides, d'Orb. Layers of flattened 

 chamberlets are disposed on either side of the chambers of the median 

 plane. Growth probably spiral before it becomes cyclical. Miogypsina, 

 Sacco. Early chambers spiral, eccentric. 



LITERATURE REFERRED TO. 



1. Archer, W. On some Freshwater Rhizopoda, new or little known. Quart. 



Journ. Micr. Sci. vol. ix. (1869), pp. 259 and 390, and vol. x. (1870), p. 110. 



2. Blochmann, F. Zur Kenntniss d. Fortpflanzung v. Euglypha alveolata, Duj. 



Morph. Jahrbuch, Bd. xiii. (1887), p. 173. 



3. Brady, H. B. Report on the Foraminifera collected by H.M.S. Challenger. 



1884. 



4. Note on the Reproductive Condition of Orbitolites Complanata : 



var. Laciniata. Journ. Roy. Micr. Soc. 1888, pt. ii. p. 693. 



5. Burrows, H. W., and Holland, R. Foraminifera of the Thanet Beds of 



Pegwell Bay. Proc. Geol. Assoc. vol. xv. (1897), p. 45. 



6. Biltschli, 0. Protozoa. Abthg. Sarkodina und Sporozoa, in Bronn's 



Klassen u. Ordnungen des Thierreichs, 1880-82. 



7. Kleine Beitrage zur Kenntniss einiger mariner Rhizopoden. Morph. 



Jahrb. xi. (1886), p. 78. 



8. Carpenter, W. B. Introduction to the Study of the Foraminifera. Ray. 



Soc. 1862. 



9. Report on the specimens of the Genus Orbitolites collected by H.M.S. 



Challenger. 1883. 



10. Chapman, F. On some New and Interesting Foraminifera from the Funa- 



futi Atoll, Ellice Islands. Journ. Liun. Soc., Zoology, vol. xxviii. p. 3. 



11. The Foraminifera. London, 1902. 



12. Cornish, V., and Kendall, P. F. On the Mineralogical Constitution of 



Calcareous Organisms. Geol. Magazine, 1888, p. 66. 



13. Dreyer, F. Peneroplis. Eine Studie zur biol. Morph. und zur Speciesfrage. 



Leipzig, 1898. 



14. Eimer, G. H. T., and Fickert, C. Die Artbildung und Verwandtschaft bei 



den Foraminiferen. Zeits. f. wiss. Zool. Bd. Ixv. (1899), p. 599. 



15. Fornasini. Secondo Contribute alia Conoscenza della niicrofauna terziaria 



Italiana. Mem. R. Accad. Sci. Istit. Bologna, Ser. 5, vol. i. (1890), p. 477. 



16. Gruber, A. Theilungsvorgang b. Euglypha. Zeits. f. wiss. Zool. Bd. xxxv. 



(1881), p. 431. 



17. De la Harpe, P. Sur 1'importance de la loge centrale chez les Nummulites. 



Bull. Soc. Geol. de France, Se"r. 3, t. ix. (1881), p. 171. 



18. Hertwig, R. Ueber Microgromia socialis. Arch. f. mik. Anat. Bd. x. 



(1874), Suppl. p. 1. 



19. Lankester, E. JR. The Structure of Haliphysema tumanowiczii. Quart. 



Journ. Micr. Sci. vol. xix. (1879), p. 476. 



