CONTRIBUTION TO THE PALEONTOLOGY OF TRINIDAD. 81 



It is very like specimens of the recent Columbella (Anachis) obesa C. B. 

 Adams from the shores of the Gulf of Mexico, but is larger and stronger than the 

 latter shell, of which it would seem to have been an ancestral form. 



Locality. — Along the shore 700 feet east of the pier at Brighton, Trinidad, in 

 an impure asphalt. 



Geological horizon. — Upper Oligocene. Approximately equivalent to the 

 Chipolan stage of Florida. 



Columbella asphaltoda new species. Plate XII, Figure 2. 



Description. — Shell of moderate size, broadly fusiform, with an acute spire; 

 number of volutions seven, of these the first two are nuclear and nearly or quite 

 smooth; subsequent whorls ornamented by regular, rather close-set, narrow, 

 sharply defined, longitudinal ribs (sixteen on the last whorl), extending from 

 suture to suture, and on the last whorl beyond the periphery, becoming obsolete 

 on the base; spiral sculpture of rather strong flattened threads, most marked on 

 the base and interspaces between the ribs, which they do not cross except at the 

 basal portion of the shell; aperture elliptical, rather short and broad, inner lip 

 not plicate, with a mere wash of callus, outer lip very slightly thickened with only 

 three or four faint lirsB within. 



Height of shell 16, greatest width 7 mm. 



Remarks. — Of the Columbellas described from the Antillean beds this shell 

 in its type of sculpture is nearest to C. venusta Sowerby from Santo Domingo and 

 Cumana, Venezuela. The latter shell is however a more slender and elongated 

 form with a strongly lirate outer lip and a plicated columella. 



This shell and C. labreana are the first Columbellas yet found in beds older 

 than Pliocene on Trinidad. 



Locality. — On the shore 700 feet east of the Brighton pier, Trinidad, in an 

 impure asphalt. 



Geological horizon. — Upper Oligocene, about equivalent to the Florida 

 Chipolan. 



Genus TROPHON Montfort, 1810. 



Trophon progne ? White. Plate XI, Figures 7, 8. 



Trophon progne White, Arch, do Museu Nac. do Rio de Janeiro, vol. VII, pp. 139-140 pi XI 

 fig. 14, 1887. P ' ' 



White's original description. — " Shell short, fusiform; spire much shorter than 

 the last volution, including the beak, volutions six or more in number, convex, 

 angular at their periphery; the last volution proportionally large; the distal 

 side of the volutions of the spire broader than the proximal side, flattened and 

 sloping outward and forward from the suture; the peripheral portion of the 

 volutions bearing prominent nodes or short varices which, on the last volution, 

 become subspinous. The surface of the distal side of the volution is marked 

 only by lines of growth, but the proximal side is marked by coarse revolving raised 

 lines, and these are crossed by distinct lines of growth; aperture large; columella 

 strong; canal short; beak reflexed. 



6 JOURN. ACAD. NAT. SCI. PHILA., VOL. XV. 



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