24 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 66 



Dimensions: Cotypes (U. S. Nat. Miis. Cat. No. 352636) measure: 

 (Larger cotype) altitude 11 mm. ; greatest diameter 5.3 mm. ; (smaller 

 cotype) altitude 7.6 mm.; greatest diameter 3.1 mm. 



Occurrence. — Middle or lower Miocene: In flood-wash. 1 mile 

 south of Brasso, Trinidad, British West Indies. 



DRILLIA RITANIDA. new species 



Plate 4, fig. 10 



Shell small, moderately stout, six and one-half whorled including 

 one and one-half nuclear whorls. Nucleus smooth and bulbous. Post- 

 nuclear whorls with a strong subsutural cord marginating the rather 

 loosely appressed suture; anal sulcus wide, slightly undulated, 

 roundly excavated and marked with two or three low spiral threads 

 and axially with arcuate growth lines. Axial sculpture of (13 on the 

 last whorl) strong, semicarinate, vertical ribs, strongest at and 

 abruptly rising from the anal fasciole, and continuing slightly re- 

 duced forward to the suture, separated by rounded excavated inter- 

 spaces of about equal width to the ribs ; on the last whorls, these ribs 

 continue to the siphonal fasciole. Spiral sculpture of about six, flat, 

 interaxial, narrow^ bands with equal interspaces; on the back of the 

 body whorl, there are 15 spirals between the anal fasciole and the 

 sij)honal fasciole — those over the base and canal being much stronger 

 and wdder spaced. Aperture obovate. Sinus rounded, moderately 

 wide and deep and situated below the subsutural cord. Canal short 

 and slightly recurved. 



Dimensions: Type (U. S. Nat. Mus. Cat. No. 115581) measures: 

 Altitude 8,5 mm.; greatest diameter 4 mm. The species is founded 

 upon a single specimen. 



Type locality : Trinidad, British West Indies. Guppy. 



This specimen with another belonging to a different species is de- 

 posited in the U. S. National Museum and was labeled Pleurotoma 

 luctuosa Orbigny, Pliocene, Guppy. The locality may be Matura as 

 P. luctuosa is listed from Matura by Guppy.^ 



The new species is somewhat similar to Drillia ehenina Dall, a 

 species reported by Dall ^° from the Pliocene to Recent, but DalFs 

 species has a greater apical angle, a smaller nucleus, and more 

 crowded spirals overrunning the base and canal than the new species 

 here described. 



DRILLIA, species, aff. D. RIOGURABONIS Maury 



Plate 3, fig. 8 



There is a single worn specimen from station 9224, Springvale, 

 which, in a general way, resembles Drillia riogurahonis Maury from 



» Sci. Asso. Proc, Trinidad, p. 159, 1867. 

 . >o Wagner Free Inst. Sci., vol. 3, pt. 1, p. 33, 1890. 



