1/6 TRANSACTIONS OF THE WAGNER FREE 



squarish behind, with a groove at the commissure and an obscure subsutural 

 ridge ; outer Up in front of the angle nearly straight, smooth inside, or with a 

 few faint granulations or lirations anteriorly ; genital sulcus well marked ; 

 canal short, recurved ; body with a wide and moderately thick coat of callus, 

 but no lirse. Max. Ion. of shell 62.0 : max. lat. 36.0 mm. 



This fine species forms, in its characters, a sort of transition from 5. albi- 

 rupianus toward S. pugilis and S. granulatus of the recent fauna, being more 

 like the latter than the former. It is also recalled by the 5. Bonellii Brogn, of 

 the European Miocene (Dax, Vienna Basin), which is a larger and less elegant 

 species. 6'. Aldrichi cannot be regarded as a link in the ancestral chain of S. 

 pugilis, since the latter was already in existence in the Haitian Miocene, but 

 its relations to 5. granulatus are closer. At all events, it combines characters 

 which in recent species seem to be parted among several specific forms. 



This species is very abundant in the Chipola beds, holding there much 

 such a place as 5. pugilis does at some points on the Floridian coast to-day. 

 It varies very much as pugilis does, having varieties corresponding to var. 

 alatus and other mutations of pugilis. The strength and to some extent the 

 character of the spirals on the last whorl varies : sometimes we have two sets of 

 coarser and finer wavy grooves, with wider, flattish interspaces ; sometimes the 

 fine grooves are obsolete and the sculpture is of wide, well-marked, rounded 

 channels, with rounded, not much elevated ridges between them. The sculpt- 

 ure of the young, as might be expected, is more uniform, and the species is 

 sufficiently characteristic to be easily recognized, even in its most extreme 

 variations. 



Strombus ehipolana n. s. 

 Plate 4, figure i. 

 ? ? Strombus bifrons Sowerby, Quart. Journ. Geol. Soc. vi. p. 49, pi. 9, fig. 9, 1850. 



Chipola beds, with 5. Aldric/ii, hut less common. Ballast Point silex-beds, 

 Tampa, Florida. 



Shell with nine or ten whorls, of which about two are small, smooth and 

 nuclear, the others ribbed, varicose, tuberculate and spirally sculptured ; early 

 whorls with twelve or more narrow, rounded ribs, gradually becoming angular, 

 tuberculate, larger, and finally tubercles pure and simple, of which there are 

 nine or ten on the shoulder of the last whorl, the last or penultimate being 

 the most prominent of all ; spiral sculpture of rounded threads, becoming 

 gradually obsolete, and on the last whorl narrower and more distant than in 

 S. Aldrichi in most cases, but varying much as in that species ; spire variable 

 in height, sometimes high and slender as in the silex-fossil figured, but gen- 

 erally much the same proportions as in 5'. Aldrichi ; last whorl attenuated 

 anteriorly; shoulder less excavated and less regular than in Aldrichi, usually 

 with two more prominent threads in front of the somewhat appressed suture ; 

 outer lip widest behind, little ascending, not reaching the suture at the begin- 

 ning of the last whorl ; commissure deep, narrow, not grooved ; there is no 



