282 TRANSACTIONS OF THE WAGNER FREE 



sents probably the middle third of the spire ; one of the whorls in it is 4 mm. 

 axially and 8.5 mm. in diameter. The whorls are as flat-sided as those of a 

 Vertagus, but the sculpture is more like that of Batillaria. It is impossible 

 to determine to what section of the genus it belongs, but it is evidently distinct 

 from any of the others described in this paper. 



Oerithium floridanum Morch. 

 Plate 14, figure 10. 

 C. floridanum Morch, Mai. Blatt. xxiii. p. 114, 1S76. 



Pliocene of the Caloosahatchie beds, Dall and Willcox. Living on the 

 east coast of the United States from Cape Hatteras, North Carolina, to the 

 north shore of Cuba, in moderate depths. 



This fine species has never been figured. The specimen selected for 

 figuring has not the outer lip and pillar as thick and the subsutural cal- 

 lus as marked as in fully adult examples, but otherwise is characteristic. 

 Its nearest relative is, perhaps, C. algicola C. B. Adams. 



Cerithium algicola C. B. Adams. 

 C. algicola Adams, Proc. Bust. Soc. Nat. Hist. ii. p. 5, 1848. 



Older Miocene of Bovvden, Jamaica, Bland ; Pliocene of Costa Rica, 

 Gabb, of the Caloosahatchie beds, Heilprin, and of Shell Creek, Willcox; 

 living on the west coast of Florida from Charlotte Harbor south to Cuba, the 

 Bahamas and Jamaica, between tides. 



This species is usually sent out under the name of atratimi. The 

 genuine atratum is easily discriminated. The specimens have been com- 

 pared with an authentic specimen received from Prof. Adams. It has not 

 been adequately figured ; the specimen illustrated in Sowerby's Thesaurus, 

 copied into Tryon's manual, is obviously a dwarf, or has been reduced to 

 about half natural size. 



Oerithiuin callisoma n. s. 

 Plate 14, figure 8. 



Pliocene of the Caloosahatchie beds, Dall. 



Shell small, acute, specimen decollate, but showing nine rounded 

 whorls, crossed by seven rounded, rather prominent ribs, which reach the 

 suture in front, but fade out before the suture behind, and are absent on the 

 last half of the last whorl ; these ribs are crossed by numerous alternated 

 threads of three sizes, of which two on the periphery and four on the base 

 are most prominent ; the base is not excavated, but the threads on the base are 

 nodulous, with deep interspaces, the posterior basal spiral is covered by the 

 suture ; the spirals behind this are plain, the two on the periphery slightly 

 swollen where they override the ribs and on the last half of the last whorl J 

 there are no varices except the ribs; suture appressed, not conspicuous; 



