318 ANTILLEAN FOSSILS— GUPPY AND BALL. vol. xix. 



ULTIMUS PRECURSOR, Dall, new species. 

 (Plate XXIX, figs. 2, 3.) 



Shell solid, i)oli.slie(l, with a strong, transverse, ronnded dorsal keel, 

 the enamel of the back leaving a considerable area uncovered; ends 

 blunt; aperture wide; the outer lip very feebly cross- striated. Lon. 

 124.5, lat. 15 mm. 



Pliocene clays of Limon, Costa Rica. No. 107456, U.S.N.M. This 

 form differs from the recent U. gihbosa by the greater excavation of the 

 slope from the dorsal keel forward, by the greater prominence of the 

 keel, which is rather more ])osteriorly situated, by the more abrui>t 

 truncation of the posterior end, and by the somewhat greater propor- 

 tional breadth. A larger area of the back is left without enamel in 

 the adult than in U. gibbom. 



CARINARIA CAPERATA, Guppy, new species. 

 (Plat.' XXYII, lijr. 14.) 



Cornucopia^form, carinated, compressed, with 7 or 8 transverse ridges 

 in harmony Avith the wavy incremental lines; keel somewhat p]i(;ate, 

 si»ire short, the apex wanting in the specimens. Lon., 7 mm. [G.J 



Shell bed of Ally Creek, Naparima, Trinidad, Guppy (2138). No. 

 107138, U.S.N.M. The shell itself being extremely fragile, can not be 

 extracted, but the casts give a fairly accurate idea of its form. It is 

 nearest to G. paretoi^ Mayer, from the Langhian (Miocene) of Senavalle 

 di Scrivia, Italy. That species is, however, much more numerously 

 and evenly sculptured with rounded riblets, and attains a length of 

 19 mm. 



TRIFORIS, doubtful species. 



Sinistral, ovate turri ted; whorls 4-0, cancellated by 4 or 5 stout re- 

 volving ridges, crossed by finer costelliB, dividing the surface into 

 rather square pits; base smooth, im]>erforate; aperture oval; columella 

 twisted, continued into a spout-like canal. Alt. 1, lat. 0.5 mm. [G.j 



Ditrupa bed, Pointapier, Trinidad, Guppy (2140). No. 107122, 

 IJ.S.N.M. While sufficient to determine the presence of the genus 

 Triforis, these minute and immature fragments are not capable of 

 affording data for a sj)ecific description. 



BITTIUM (STYLIFERINA) CERITHIDIOIDE, Dall. 



Oligocene of Januiica, C^u])py (2()4). No. 107123, U.S.X.M. This 

 widespread little shell extends from the Oligocene to the recent fauna of 

 the Antilles with great uniformity of character. 



BITTIUM (STYLIFERINA) PRiEFORMATUM, Guppy, new species. 



(Plate XXVI II, fig. 2.) 



Turrited, subulate, or rather fusiformly cylindrical, varicose, si»irally 

 lirate, and grauulose; whorls about 12, slowly increasing, the last 



