358 FORAMINIFERA OF THE CRAG. 



PoLTSTOiiELLA M aceTjTj A, ParTcei' and JoTies, 1860. Ann. Mag. Nat. Hist., ser. 3, 



vol. V, p. 104, No. 8 ; p. 290, No. 70 ; 

 vol. vi, p. 339, Nos. 2, 3. 



— TENUissiMA, Karrer, 186-1. Novara-Exped. geol. Theil, vol. i, 



p. S3, pi. xvi, fig. 16. 



— MACELLA, P., J., and B., 1871. Ann. Mag. Nat. Hist., ser. 4, 



vol. viii, p. 239, No. 101, pi. xii, 

 fig. 154. 



— LAMiNATA, Terqicem, 1878. Mem. Soc. Geol. Prance, s6r. 3, vol. i, 



Mem. iii, p. 16, pi. i (vi), figs. 8 a, b. 



— — — 1882. Ibid., vol. ii, Mem. iii, p. 47, pi. ii (x), 



figs. 24 a, h. 



— MACELLA, Srady, 1884. ' Challenger ' Report, p. 737, pi. ex, 



figs. 8—11. 



— — B., S., and B., 1890. Journ. R. Micr. Soc, p. 563, 



pi. xi, figs. 26 a, b. 



— — Mgger, 1883. Abhandl. k. Bayer. Akad. Wiss., vol. 



xviii, p. 432, pi. xx, figs. 22, 23. 



Characters. — Compressed, explanate, umbilicus depressed ; margin more or less 

 acute ; chambers narrow, curved. 



So far as essential particulars are concerned, the description of Fohjstomella 

 crista would apply equally to P. macella. There are, however, distinctions which 

 tend to place P. iiiacella in the light of a starved modification of the type. 

 P. macella, whilst having a lateral surface as large as that of P. crispa, is much 

 thinner than the typical form, and is subject, as shown in Fichtel and Moll's 

 figures, to lateral deviations from the symmetrical plan of growth. The peripheral 

 margin is generally even, and not tubercular or spinose as in P. crisjoa, 

 P. regina, &c. 



Occurrence. — Polystomella macella is stated by Brady in the ' Challenger ' 

 Report to be " not common in the Northern Temperate Zone; the Mediterranean 

 and the Adriatic being apparently its boreal limit." We have, however, well- 

 marked specimens in our own collection from the southern coast of England. 

 The published records show that it is very generally distributed as a shallow-water 

 form as far south as Kerguelen. 



Its geological range, so far as is at present known, extends to the Middle 

 Jurassic of Russia. It has also been recorded from the Red Chalk of Speeton ; 

 from the Eocene of the Paris Basin ; from the Miocene of Vienna, Bavaria, 

 and Muddy Creek, Victoria ; from the Pliocene of Italy, Kar Nicobar, Isle 

 of Rhodes, and St. Brth. It is not uncommon as a Pleistocene fossil. In the 

 Coralline Crag we have found specimens in every zone e.xamined ; but, unlike 

 P. crispa, the species has not been found in the Upper Ci'ag. 



