186 Messrs. Parker and Jones on 



26, Gr. divergens, is a subconical delicate B. punctata ; 27, Gr. 

 lineare^ is a delicate subcylindrical B. punctata of typical 

 character ; 28, Gr. rhomhoidale, is a relatively large VirguUna 

 squamosa. VirguUna is a subgenus of BoUvina^ having 

 flattish, smooth, and delicate shells, with extremely fine pores, 

 and with the chambers built up more or less regularly anglewise ; 

 whilst BoUvina is coarser in shell-structure, and its chambers 

 are rounder, or at least shorter transversely. VirguUna squa- 

 mosa comprises the very regularly Textilariform varieties ; 

 V. Schreihersii takes those that have long inflated chambers, 

 variously arranged, parallel with the axis of the shell, or nearly 

 so — sometimes resembling a Polymorphina, sometimes modi- 

 fied by a partial twist of growth and passing towards BuUmina 

 proper, of which genus both BoUvina and VirguUna are 

 sections. 



Fig. 29, Proroporus verrucosus^ is a tuberculated or coarsely 

 granular entosolenian Polymorphina tuherculata^ and may be 

 added to the synonymy of that species in the " Monograph of 

 Polym.orpliina^'' Linnean Soc. Transact, vol. xxvii. p. 242. 

 Fig. 30, Polymorphina glabra, is VirguUna squamosa ; and 31, 

 P. asparagus, is a narrow subvariety of the same. Figs. 

 32-36 are various small individuals of VirguUna Hemprichii 

 (Ehr.), described more fully in the ' Geol. Mag.' no. 89, 

 p. .509 ; and they represent forms that may be said to be trans- 

 itional between V. Schreihersii and BuUmina proper (32, Stro- 

 plioconus ovum. ; 33, 8tr. cepa ; 34, Str. jlosculus ; 35, Str. 

 gemma', 36, Str. gracilis). Fig. 37, GuttuUna turrita, = Ver- 

 neuilina pygmcea (Egger) ; 38, Pleurites turgidus, = VirguUna 

 Hemprichii (see above) ; an aperture, visible on the inner side 

 of the terminal chamber, is diagnostic, as in pi. xxviii. f. 30, 

 showing the really Bulimine character of the shell, and indi- 

 cating the passage of the Virguline into the Cassiduline section 

 of this genus. 



Fig. 39, Vaginulina linearis (fragment), ■=-Marginulina 

 ensis, Reuss (' Bohm. Kreid.' ii. pi. 13. fig. 27). Fig. 40, 

 Vagimdina acuta (fragment), belongs to the CitJiarina section 

 of the subgenus. Fig. 41, Planularia tenella, is a delicate 

 young or arrested Cristellaria, such as in the full-grown state 

 would arrive at either the Planularian or the Marginuline con- 

 dition. 



Fig. 42, Nodosaria aculeata, is a very interesting thick- 

 shelled and elongate variety of N. radicula, having numerous 

 prickles, chiefly but not wholly on the base of the chambers, 

 pointing backwards. Oblique and tapering (Dentaline) sub- 

 varieties of this form have been plentifully met with in Ter- 

 tiary strata, as Dentalina Adolphina D'Orb. (almost straight 



