l(i MAKOINKLLA. 



Dicision II. Sjjecies icitJiout hasal niiiua. 



Section 1, (Prunum, Adams, Eyouena, Jouss. for most part). 

 Group a. {Labiatce\ 31. labiata, Kiener, M. oblonga, Swn. 

 " b. {OuttatcB). M. guttata, Dillw. M. apicina, Mke. 

 " c. {Marginatce}. M. marginata, Born, M. prunum, Gmel. 

 Section 3. 



Group a. ( Volvaria, H. and A. Ad.). M. pallida, Linn. 

 " b. (Canalispira, Jouss. '. M. 01 ivellceform is, Jouss. 

 Sections. [Voh-arina, H. and A. Ad., and Ballanetta, Jouss.). M. 

 triticea. Lam., M. zonata, Kiener, M. cylindrica, Sowb. 



Wemkuuff',in 1880, published an excellent synonymic catalogue 

 of the genus, in the Jahrbiicher der Deutsch. Mai. Gesell. ; 

 arranged as above. 



In addition to the names enumerated above, Mr. T. A. Conrad 

 has proposed three fossil groups, neither of which he has char- 

 acterized. 



Po7-cellanella. Type P. bella. Miocene. The species was 

 not described until 1868, six years after the name was cited in 

 connection with PorceUaneUa, and then it was placed under 

 Prunum, so that Conrad abandoned this group. 



Microspira, Conrad. Proposed as a subgenus of Volutella, 

 Swainson, the t3'pe being M. oviformis, a miocene species, pre- 

 senting no generic characters to distinguish it from numei-ous 

 recent Marginellas. (AI. oviformin, Conrad. Manual, vol. iv, 

 t. 3, f. 42.) 



Bidliopsis, Conrad. Type, B. cretacea, Conr. (PI. 3, fig. 29). 



The onl}^ objection to Weinkauff 's arrangement of the species 

 is that the basal sinus is more or less apparent in the species, so 

 that they form no sharply defined groups : on the other hand 

 he has the advantage over Jousseaume, Adams, etc., in clearl^^ 

 recognizing their artificial nature and subordinate value, by using 

 the terms division, section and group instead of genus and sub- 

 genus. The number of species in the genus is so large that it is 

 convenient to group them as nearly as possible in accordance 

 with characters which appear to be comuion to several of the 

 forms, and for this purpose I shall use some of the systematic 

 terms heretofore proposed, assigning to them no value, however, 

 except tliat of mere convenience. 



