26 FORAMINIFERA OF THE CRAG. 



from the chambers alternately from their sides as well as from their fronts, giving the shell 

 a loosely Textularian character ; its chambers are usually somewhat pyriform. In deep 

 Mediterranean soundings; and in the Chalkmarl ('Q. J. G. S.,' loc. cit. ; Carpenter's 

 ' Introd./ loc. cit., fig. 10). 



3. Webhina irregularis clavata, P. & J., is also a fixed form, and consists frequently of 

 a single pyriform chamber, tabular at one end, and bearing a slightly margined and semioval 

 aperture at the other. The tubular portion frequently gives ofi' another tube and chamber, 

 thus almost identifying itself with the bifurcating forms of W. irregularis proper. Common 

 at great depths in the Mediterranean and South Atlantic (' Q. J. G. S.,' loc. cit. ; Car- 

 penter's ' Introd.,' /. c, figs. 6, 7). 



4. Webbina irregularis hemisplimrica, nov. The specimen from the Crag described 

 further on, barely separable from the last. 



Trochammina (proper) is typified by Tr. squamata, P. & J., comprising five known 

 varieties, which have spiral shells, more or less rotaliforra in their growth. 



1. The simpler of these forms, such as Tr. squamata incerta {Operculina incerta, D'Orb., 

 'For. Cuba,' p. 49, pi. 6, figs. 16, 17; Spirillina arenacea,'^''^\z.ms,QW_, 'Monog. Brit. For.,' 

 p. 93, pi. 7, fig. 203 ; Ammodiscus (?), Reuss, 'Sitz. Akad. Wien.,' 1861, vol. xliv, p. 365), 

 consist of a long, spiral, undivided chamber, having the shape of the clear, perforated, 

 discoidal Spirillina vivipara, Ehrenb., and of the white opaque Cornuspira foliacea, Phil. 

 Living in the Atlantic ; common at great depths in the Mediterranean. Fossil in the 

 Gault, Lower Oolite, &c. (See ' Q. J. G. S.,' /. c. ; and Cai-penter's ' Introd.,' /. c, fig. 2). 



2. Tr. squamata charoides, P. & J., is a similar undivided tubular chamber vertically 

 spiral, presenting a resemblance to the fruit of the Chara. Common in deep water; 

 Mediterranean, Red Sea^ and South Atlantic (' Q. J. G. S./ I. c. ; and Carpenter's ' Introd.,' 

 I. c, fig. 3). 



3. The third variety, Tr. squamata gordialis, P. and J. (' Q. J. G. S.,' /. c. ; Car- 

 penter's ' Introd. For.,' /. c, fig. 4 ; Parker and Jones, ' Phil. Trans.,' vol. civ, p. 408, 

 pi. 15, fig. 32), has more than one chamber, the shell in the early stage being formed of a 

 few spirally arranged, but variable chambers ; and at a later period they are moulded on 

 an undivided vermiform sarcode, sometimes slightly constricted at intervals, and either 

 discoidal or irregularly elevated ; often passing at nearly right angles over the primary disc, 

 or forming sudden loops and twistings. It lives in the Red, Indian, and Arctic Seas. 

 The "Permian" >iSi?r;3Z(!/ajOMS27/« of Schlotheim {8piriUinapusiUa,ionQ^; Miliola i^) pusilla, 

 Kirby), and some forms of the Cretaceous (?) Trochammina proteus of Karrer, belong to 

 the same. Indeed, the excellent figures of T. proteus, in Dr. Karrer's paper on the Old 

 Vienna Sandstone, ' Sitz. Akad. Wien. Math.-Nat. CI.,' vol. lii, 1 Abth., 1865, pi. 1, 

 figs. 1 — 8, comprise modifications of Tr. gordialis (figs. 1, 2, 3, 8), charoides (fig. 4), 

 squamata (fig. 6), and irregular squamata, or passage from lobulate gordialis to squamata 

 (fig. 5). We may also remark that fig. 10 (named Cornuspira Hoernesi) is probably 

 Trochammina incerta. 



