386 TRANSACTIONS OF THE WAGNER FREE 



umbilical carina is marked by two coarsely beaded spirals, the whole crossed by 

 elevated, sometimes imbricated, radiating lines in harmony with the lines of 

 growth. The base recalls that of A. longispina Lam., but the upper surface is 

 quite different from that species. The specimens are about 5 mm. in greatest 

 diameter and 3.5 mm. high. I have thought it best not to apply a name tb 

 these specimens, though they evidently represent a new species. 



Genu.s COLLONIA Gray. 



Collonia Gray, in Figs, of Moll. An. iv. p. 87, 1850, type Delphinula inarginaia Lam. 

 Tuba Gray, P. Z. S. 1S47, p. 144. Not of Lea. 



Collonia Gray, Guide Moll., i. p. 143, 1847 ; Carpenter, Proc. Gala. Acad. Sci. iii. p. 175, 

 1864. Not of H. and A. Adams, Gen. Rec. Moll. i. p. 396, 1854. 



The fluctuations of the synonymy of this group have been recapitulated 

 by Carpenter as above cited. The shells typified by Delphinvla niarginata 

 Lam. carry the name. The species here figured and described have not 

 afforded any specimens of the operculum, but they agree exactly in general 

 character and especially in the features of the aperture, and I do not doubt 

 their pertinence to the genus as above restricted. 



The singular umbilical rib is reproduced in the young of sundry species 

 of Oniplialius, from the adult of which the same parts are markedly different. 



I have not seen the operculum of the Parisian shell, and confess to some 

 suspicion as to the combination of a thick, heavy calcareous operculum like 

 that of Callopoma with the comparatively thin shell to which it has been as- 

 signed. But for the present I shall leave the group where Gray placed it, 

 although its relations appear to be much more directly with such Trochidce as 

 OinpJialius, or with the CyclostreinatidcB, judging by the shell alone. 



The group appears first in the Claibornian, if I have correctly estimated 

 the small species here described from thence. It also existed in the Chipola 

 Older Miocene, disappeared during the Chesapeake refrigeration of these 

 shores, and reappeared in the warmer Pliocene. No recent species are yet 

 known from America. 



The general form of the shells of this genus is more like an elevated 

 Cyclostrema than a heavy turbinate Omplialius, and the outer lip is expanded 

 and slightly thickened. The shell is small and relatively thin compared with 

 Oviphaluis. The sulcus in the lip and the peculiar umbilicus forbid its asso- 

 ciation with Cylostrema, and the thickened and reflected lip distinguishes it from 

 Solariella. It may perhaps bear to Callopoma somewhat such a relation as 

 Solanderia does to Gibbula. From Conradia it is separated easily by its thick- 

 ened and reflected lip; and from Haplocochlias , otherwise verj^ similar, by its 

 umbilical characters. 



Collonia elegantula n. s. 

 Plate 19, figures 3, 4. 

 Newer Miocene of the Cape Fear River, North Carolina? Johnson; Plio- 



