SPIRILLINA VIVIPARA. 289 



CoBNTTSPiBA PERFORATA, Schultze, 1854. Organ. Polytlial., p. 41, pi. ii, fig. 22. 

 Spibillina VIVIPARA, Parker and Jones, 1857. Ann. Mag. Nat. Hist., ser. 2, 



vol. xix, p. 284, pi. xi, fig. 46. 

 Ctclolina impressa, Egger, 1857. Neues Jahrb. f. Min., &c., p. 304, pi. x, 



figs. 7, 8. 

 Spibillina perforata, Williamson, 1858. Eec. For. G-t. Br., p. 92, pi. vii, 



fig. 202. 



— VIVIPARA, P. and J., 1860. Quart. Journ. Geol. Soc, vol. xvi, p. 303, 



No. 86. 



— — — 1865. Phil. Trans., vol. civ, p. 397, pi. xv, 



fig. 28. 



— PERFORATA, Alcock, 1865. Proc. Lit. Phil. Soc. Manchester, vol. iv, 



p. 206. 



— — Parfitt, 1869. Trans. Devon. Assoc, vol. iii, p. 74 (16 



of Cat.). 



— VIVIPARA, P. and J., 1872. Ann. Mag. N. H., ser. 4, vol. ix, p. 221. 



— — Siddall, 1878. Proc. Chester Soc. N. Sci., No. 2, p. 55 



— — Mobius, 1880. Foram. Mauritius, p. 88, pi. viii, figs. 1, 2 



(a single row of pores near the outer 

 wall on the older whorls). 



— — Bradi/, 1884. Eeport ' Challenger,' p. 630, pi. Ixxxv, 



figs. 1 — 5. 



— OBCONicA, Brady, 1884. Ibid., figs. 6, 7 (a medial row of pores). 



— VIVIPARA, BaJkwill and Wright, 1885. Tr. E. I. Ac, vol. xxviii (Sci.), 



p. 348, pi. xii, fig. 32. 



— IMPRESSA, Giimbel, 1885. Geol. Bayern, vol. i, part 2, p. 421, 



fig. 266 13. 



— VIVIPARA, Bradj/, 1887. Journ. E. Micr. Soc, p. 917. 



— — Hdmler, 1890. Abh. Schweiz. Pal. Ges., vol. xvii, p. 122, 



pi. XV, fig. 49. 



— MINIMA, Schacko, 1892. Arch. Freund. Nat. Mecklenburg, Jahr. xlv 



(for 1891), p. 159, pi. o, figs. 4a, J. 



— VIVIPARA, Egger, 1893. Abhandl. k. Bayer. Ak. Wiss., vol. xviii, 



pt. 2, p. 394, pi. xviii, figs. 56—58. 



Characters. — lu the type-form the shell is discoidal, thiu, sometimes concave 

 in the middle; rounded on the edge, the whorls being sub- cylindrical, rarely 

 embracing, but the later usually larger in diameter than the earliest ; bearing 

 numerous conspicuous foramina. 



The variety here figured differs from the type-form in being marked by a 

 single row of impressions or perforations along the inner edge of the sub- 

 cylindrical tubular whorls. We had prepared to call it itnilinearis, but Dr. G. 

 Schacko, of Berlin, has figured and described a very simihir, if not identical form, 

 as above quoted. The large perforations along the suture-line, besides the fine 

 general perforation, are characteristic. The apparent granulation of the surface 

 in his specimen M. Schacko attributes to a partial decalcification of the shell. 



