BILOCULINA RINGENS. 95 



MiLioLiNA BiNGENs, Goes, 1889. Bihang k. Svensk. Akad. Handl., vol. xv, part 4, 



No. 2, p. 14, pi. ii, figs. 7, 13, and 14. 

 BiLocuLiNA BINGENS, Terrigi, 1889. Atti E. Ace. Lincei Mem., ser. 4, vol. vi, 



p. 107, pi. iv, fig. 1. 



— — Egger, 1893. Abhandl. k. Bayer. Akad. Wiss., vol. xviii, 



p. 220, pi. i, figs. 7—9. 



— INTERMEDIA, Fomasim, 1893. Mem. E. Accad. Bologna, ser. 5, vol. iii, 



p. 440, pi. i, figs. 1, 1 a. 



(Note. — In the reference to P. and J., 1857, in the synonymy given at p. 5 of Part I, figs. 32 

 and 33 should be omitted, being probably striated forms of B. bulloides.) 



The aperture usually consists of a transverse slit, but varies in relative size 

 and in the shape of the tongue-like valve, not only in those mentioned in the 

 synonymy, but also in others, among which are several that have received from 

 M. Schlumberger the specific names of Bradiji {ringens. Rep. ' Challenger,' p. 142, 

 pi. ii, fig. 7), vespertillo {ringens, ibid., fig. 8), Fischeri, Milne-Edwardsi, pisum, 

 anomala ?), in ' Mem. Soc. Zool. France,' vol. iv, pp. 166 — 182, pis. ix — xi, figs. 55, 

 &c., and woodcuts. The B. ringens, Schlumb., ' Bull. Soc. Geol. France,' ser. 3, 

 vol. XV, pi. XV, figs. 14 — 18, have subcircular apertures. 



Goes unites with the typical Biloculina (Miliolina) ringens (figs. 7, 13, and 14, 

 pi. ii, ' Bihang k. Svensk. Vet.-Ak. Handl.,' vol. xvi, part iv. No. 2) several varieties 

 of triloculine growth. 



Taking a group of Biloculina belonging to B. ringens as far as the transverse 

 slit-like mouth is concerned (for example, some figured in d'Orbigny's ' Foram. 

 Foss. Vienne,' 1846), we may notice that they vary from lenticular to subrotund 

 and subovate, thus : 



1. Lenticular, B. lunula, p. 264, pi. xv, figs. 22 — 24 [B. depressa]. 



2. Sublenticular, B. affinis, p. 265, pi. xvi, figs. 1 — 3. 



3. Subrotund, B. simplex, Tp. 264, pi. xv, figs. 25 — 27. 



4. Subovate, B. chjpeata, p. 263, pi. xv, figs. 19 — 21. 



5. Subpyriform, B. inornata, p. 266, pi. xvi, figs. 7 — 9. 



The last (No. 5) has a contracted, subcircular, and slightly projecting aperture, 

 thus approaching B. hulloides, with which we group it now as a variety. 



An interesting group of Biloculinse were figured (but not named nor described) 

 by Dr. G. C. Wallich in 1862, " The North Atlantic Sea-bed," part i, pi. v, 

 namely, fig. 1, Biloculina ringens ; figs. 2, 5, and 8, B. depressa ; figs. 3, 4, and 6, 

 B. hulloides. They escaped notice in Part 1 of this Monograph, 1866, but are 

 well worthy of attention. See also a group of B. ringens and varieties in 

 Schhcht's ' Foram. Septar.-Thones Pietzpuhl,' 1870, pi. xxxv, figs. 27—29, 33— 



