388 Messrs. Jones, Parker, and Kirkby on the 



the former whorls of the shell at various angles. On the other 

 hand, the recent contorted forms are associated with others of 

 similar structm'e and habit, but more or less discoidal in their 

 mode of growth, leading us towards both Trocliammina incerta 

 (D'Orbigny, sp.) and Tr. injlata (Montagu, sp.) ; and, indeed, 

 all these and other varieties were, in 1860, included under the 

 "second species" of Trochammina^ ^ as being zoologically 

 related to the typical Tr. squamata ; but, of com'se, the neces- 

 sity of retaining binomial appellations for well-marked varie- 

 ties, recent and fossil, must be always recognized. For these 

 chief varieties, then, the names Tr. incerta (D'Orb.), Tr. clia- 

 roides (P. & J.), Tr. gordialis (P. & J.), Tr. squaniata(P. & J.), 

 and Tr. injlata (Montagu) were adopted f. 



In a paper " On the Occurrence of Foraminifera in the older 

 beds of the Vienna Sandstone," F. Karrer has given excellent 

 figures of his Trocliammina jproteusX from these strata of Cre- 

 taceous or Lower-Tertiary (?) age. Among these figm-es we 

 find modifications of Tr. gordialis (figs. 1, 2, 3, 8), of charoides 

 (fig. 4), oi squamata (fig. 6), and irregular squamata^ or trans- 

 itional from lobulate gordialis to squamata (fig. 5). The 

 Spirilline or discoidal and narrow- whorled condition {Tr. in- 

 certa)^ from the same beds, is given as Gormis])ira Hoernesi 

 (fig. 10). 



§ VI. Witli some of the above-mentioned recent and fossil 

 forms the different specimens of the little Permian fossil under 

 notice are readily correlated. Thus the perfectly discoidal 

 narrow-whorled individuals come in the same group with Tr. 

 incerta ; and very similar Rhizopods, having piano-spiral 

 shells of sandy texture, have been figured and described from 

 several geological formations, and have received different 

 names, as shown in the following list : — 



Recent. Operculina incerta, D'Orbigny, 1839. Foram. Cuba, p. 49, pi. 0. 



figs. IG, 17. 

 Lower Cretaceous. Operailma ci-etacea^ Reuss. 1846. Verstein. Bohui. 



Kreid. p. 35, pi. 13. tigs. 04, G5. 

 Lias. Orhis injiimis, Strickland, 1848. Quart. Journ. Geol. Soe. vol. ii. 



p. 30, fig. a. 

 Permian. Spirilltna, sp., .Tones, 1850. In King's Monogr. Perm. Foss. 



pp. 18-20 ; and in Morris's Catal. Brit. Foss. 2nd edit. p. 42. 

 Clialk and Chalk-marl. Spirillina cretacea, Jones, 1854. In Morris's 



Catal. Brit. Foss. 2nd edit. p. 42. 



* Quart. Journ. Geol. Soc. vol. xvi. p. 304. The " first species," or 

 simplest form, has been since referred to the restricted genus " IFebbina" 

 D'Orb. 



t Op. cit., and in Carpenter's ' Introd. Foram.' p. 141, pi. 11. figs. 1-5. 



\ Sitz. Akad.Wien, Math. -Nat. Classe, vol. Hi. 1st Abthcil. 1805, pi. 1. 

 lias. 1-8. 



