468 Messrs. W. K. Parker and T. R. Jones on the 



bers, after having developed the triangular portion, to become 

 dimorphous, taking on a new character of growth namely, that 

 seen in Bulimina, where several oblong parallel cells are taken 

 up in the formation of the round advancing coil. Specimens 

 showing the combination of Verneuiline and Bulimine growth 

 occur fossil at Grignon and recent in Australia. In many spe- 

 cimens, however, the triangular growth is masked, and the pe- 

 culiar valve of the aperture is required to aid us in discriminating 

 the varieties of Valvulina from those of Bulimina. Such a one is 

 the V. gibbosa, D'Orb. (Mem. Soc. Geol. France, iv. p. 38. pi. 4. 

 f. 1, 2). 



Besides these short and variously coiled Valvulina, there are 

 others, taking long or claviform shapes, resembling nails. Of 

 these elongate varieties one is figured in Lyell's ' Principles of 

 Geology/ pi. 4. f. 12-14, and < Manual/ 5th edit. f. 239 (Cla- 

 vulina corrugata, Desh.). The valve is well shown in the draw- 

 ing, and the chambers may be seen to pass from a triserial to 

 a uniserial arrangement, still fitting obliquely on each other. 

 Between this and the typical V. triangularis there is a regular 

 series of gradation. A neater form than C. corrugata is the 

 C. Parisiensis, D'Orb. (Modeles, No. 66) ; in the specimen 

 modelled, the large round terminal aperture has accidentally lost 

 its valve-like process. The chambers of the produced part are 

 here conformably adapted one to another, and there is a marked 

 distinction between the triserial and uniserial portions. Sub- 

 varieties of this form are common, not only in the Grignon 

 deposits, but also recent in the Indian and Australian seas. 



A modification of Valvulina nearly allied to C. Parisiensis is 

 the C. angularis, D'Orb., Ann. Sc. Nat. vii. p. 268, pi. 12. f. 7 

 (figured also as C. tricarinata, D'Orb. For. Cuba, pi. 2. f. 16-18). 

 This variety, which also is an inhabitant of the eastern seas, 

 differs mainly from the last in attaining a much larger size, and 

 in keeping a tricarinate form throughout its length. A still 

 nobler Clavulina, but having five carinse along its uniserial por- 

 tion, is common in company with the last two in the shelly 

 deposits of the coral-reefs of Australia. 



The specimen figured by Lamarck is a long Clavulina closely 

 related to those above mentioned ; but it presents us with an 

 extreme development of the uniserial chambers, the coiled por- 

 tion being nearly obsolete. By D'Orbigny this shell is named 

 Nodosaria (Orthocerina) Clavulus (Ann. Sc. Nat. vii. p. 255), and 

 is represented by his Model No. 2. This model fails to exhibit 

 the slightly coiled commencement, which is constant in this 

 variety, and some traces of which may be recognized in Lamarck's 

 sectional view of the shell (Tabl. Enc. Meth. pi. 466. f. 3 b). 

 This is a common Foraminifer at Grignon. 



