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



descendente, calloso, triangulato-reflexiusculo, cum basali angulum 

 efformante, ad angulum acute et profunda inciso ; periomphalo 

 pone rimam oblique compresso vel obtuse carinato. 



Sp. descript. diam. major 11, minor 10, axis 6 J mill. 



Majoris imperfect! diam. major 16, minor 13^, axis 8| mill. 



Habitat prope Moulmein. 



The singular rift at the base of the columella in this species 

 reminds the observer of some of the Helicinida^ ; yet the aspect 

 of the shell and its evident affinity to H. Calias and H. forabilis 

 proclaim its relation to Helix. The attention of the discoverer 

 has been called to the acquisition of living specimens at a more 

 favourable season, and to the observation of the main external 

 characters of the animal. 



Cheltenham, April 30th, 1859. 



XLVIII. — On the Nomenclature of the Foraminifera. 

 By W. K. Parker, M. Micr. Soc, and T. R. Jones, F.G.S. 



I. On the Species enumerated by Linnaeus and Gmelin. 



In our former paper descriptive of some Foraminifera from the 

 coast of Norway (Ann. & Mag. Nat. Hist. ser. 2. vol. xix. p. 273), 

 we offered some general observations on the character and rela- 

 tions of these minute Rhizopodous creatures, especially pointing 

 out the wide limits within which the species range under innu- 

 merable varieties of form and features. In this and some other 

 papers which we hope to communicate from time to time, we 

 propose to attempt the definition of some at least of the specific 

 forms, and to settle the correct nomenclature of this interesting 

 Microzoan group. In carrying out our intention of determining 

 the true specific characters of the Foraminifera, we have neces- 

 sarily had to compare the figures given by the older naturalists 

 both with each other and with the more modern drawings pub- 

 lished by others, as well as with the numerous specimens which 

 we have of late been able to gather. 



The principles which guide us in this examination have been 

 already dwelt upon in the memoir above referred to, as well as 

 in the paper on the Miliolitidce by one of us in the ' Quarterly 

 Journal of Microscopical Science,' No. 23. p. 53. We especially 

 refer the reader to the introductory portions of the memoirs by 



* The columellar slit in Helix schistostelis represents the correspon^ng 

 feature in Alcadia, Gray, while the umbilical keel and columellar rift bear 

 an analogical resemblance to those observable in Stoastoma, Adams. Thase 

 two operculated genera inhabit the West Indies. The North American 

 construction of Helix pylaica, B., was noticed in a former paper on Burmese 

 Helices. 



