316 Mr. F. Chapman on 
Involutina aspera, Terquem, 1863, ibid. for 1862-1863, p. 221, pl. x. 
fig. 21 (Troisitme Mém. Foram. "du Lias). 
Cornuspira oolithica, Schwager, 1867, in Waagen’s Ueber die Zone des 
Amm. Sowerby2, vol. 1. pt. 11. p, 655, pl. xxxiv. (xi.) fig. 4 
Trochammina incerta, Parker, Jones, and Kirkby, 1869, Aun, & Mag. 
Nat. Hist. ser. 4, vol. iv. p. 388, pl. xiii. fig. B. 
Cornuspira helvetica, C. eichbergenensis, C. elliptica, &e., Kiibler and 
Zwingli, 1870, Foram. Schweiz. Jura, pp. 18, 17, 24. Figures 
distributed in pls. ii., iii., and iv. 
Cornuspira granulosa, C. infraoolithica, &c., Terquem, 1870, Troisiéme 
Mém, Foram. du Syst. Oolithique, pp. 242-244, pl. xxv. figs. 12-20. 
Trochanamina incerta, Brady, 1876, Monogr. Carb. and Perm. Foram. 
(Pal. Soe.), p. 71, pl. ii. figs. 10-14; Tate and Blake, 1876, The 
Yorkshire Lias, p. 452, pl. xvii. fig. 17; Heeusler, 1883, Neues 
Jahrb. f. Min. Bd. i. p. 59, pl. iv. fig. 1. 
Ammodiscus incertus, Brady, 1884, Chall. Rep. vol. ix. p. 330, 
pl. xxxviii. figs. 1-3; L. G. Borneman, 1886, Rete zur Kennt- 
niss des Muschelkalks, Jahrb, k. preuss, geol. Landesanst., Berlin, 
p. 298, pl. xiii. figs. 8, 4; Heeusler, 1890, Abhandl. Schweiz. paleon- 
togr. Gesellsch. vol. xvii. p. 55, rl. ix. figs. 1-21; Crick a Sher- 
bor, 1891, Journ. Northampton Nat. Hist. Soc. vol. vi 209, 
fice, Al, 
The above synonymy refers to the more important notices 
of Ammodiscus incertus, and relates chiefly to its occurrence 
in Paleozoic and Jurassic strata. The specimens of A. ¢n- 
certus from the Rhetic beds of Wedmore often show a 
tendency to depart from the ordinary plano-spiral and circular 
form, being more or less elliptical and irregularly coiled; in 
the latter character they closely approach A. gordialis. These 
features are not unusual with many of the Carboniferous and 
Permian examples recorded by Dr, H. B. Brady, and also in 
the Jurassic forms described by Dr. Heeusler. In the Rhetic 
specimens the tests are composed of fine quartzose sand, and 
some of the fossils have a conspicuously opaque white appear- 
ance in the washings, whilst others, more obscure in their 
general external characters, are of a brown colour. 
This species occurs commonly in many British Carbon- 
iferous limestones, in the Permian magnesian limestones of 
England, and in the Zechstein and Muschelkalk of Germany. 
It is also abundant in Jurassic strata, and is met with in 
nearly all later fossiliferous deposits. 
Frequent in the Rhetic of Wedmore, bed no. 2. 
8. Ammodiscus anceps (Brady). 
(Pl. XI. figs. 10 a, 2.) 
Trochammina anceps, Brady, 1876, Monogr. of Carb. and Perm, 
Foram. (Pal. Soc.) p. 76, pl. ii. figs. 8a, d. 
The characters of this species as given by Dr. H. B. 
Brady apply very nearly to the Rhetic specimens, and are as 
