INSTITUTE OF SCIENCE, PHILADELPHIA. 99 



The larval shell without the protoconch appears to have had not to exceed 

 one short whorl with incremental stri^, but it is, in the absence of a complete 

 specimen, unsafe to form a conclusive opinion on this point. The minute 

 sculpture of the young is exactly that of T. scolymiis, but in the adult the fine 

 sculpture and ribbing are obsolete and the body-whorl is inflated and nearly 

 smooth. The pillar is straight, short, with a deep umbilical foramen, the whole 

 shell is thin and light, considering its size. The suture is distinct and lies on 

 a thin band of callus, in the last whorl, which extends a little behind the 

 suture. The adult figured is 231 x 140 mm., but when perfect was about 260 

 mm. in length. The young tip figured has a length of 33.0 mm. The former 

 was obtained by me from the Pliocene marl on the Caloosahatchie River, but 

 specimens were subsequently collected on Shell Creek from the equivalent 

 horizon by Mr. Willcox. 



T. validus Sowerby has a channelled suture and small, rounded tubercles. 

 It has not been figured, but would appear to be distinct. Fasciolaria textilis 

 Guppy (Geol. Mag. 1874, pi. xvi. fig. i) is a young Turbinella and may possi- 

 bly prove, when adult specimens are found, to be identical with some of the 

 species here discussed. 



Subgenus Vasum (Bolten) Link. 



By a lapsus pennce the synonym, Cynodonta of Schumacher, was used by 

 me in my Catalogue of the Marine Mollusks of the Southeastern Coast of the 

 U. S., Bulletin of the U. S. Nat. Museum No. 37. The name Vasum, though 

 without standing from Bolten's use of it, derived authenticity from its defini- 

 tion by Link, who preceded Schumacher by some years. 



Vasum horridum Heilprin. 

 V. horridum Heilprin, op.cit. pp. 75, 132, pi. 4, figs. 6, 6 a ; pi. 16 a, fig. 72, 1S87. 



Caloosahatchie beds, Pliocene marls of South Florida. 

 This magnificent species seems to be confined to these beds and to have 

 given rise to no descendant in the recent fauna. 



Vasum subcapitellum Heilprin. 

 Plate 4, figure 12. 

 V. subcapitellum Heilprin, op. cit. p. 109, pi. 15, fig. 44. Compare Turbinellus tzdificatus 

 Guppy, Journ. Geol. Soc. Lond., Nov. 1S76, p. 523. 



Miocene silex-beds of Ballast Point, Tampa Bay. Dall, Willcox, Burns 

 and others. 



I agree with Prof Heilprin in regarding this species as specifically distinct 

 from V. capitellum of the recent fauna, and also as being probably ancestrally 

 related to it. 



