40 PROCEEDINGS OF THE NATIONAL. MUSEUM vol. 66 



spects: The spire is a little longer and the apical whorl less truncate; 

 the body whorl is more shouldered below the suture and more de- 

 pressed at the posterior third ; the outer lip possesses a stronger mar- 

 ginal varix, and the inner margin one more denticle at the anterior 

 end. Otherwise the variety is very similar to Guppy's species, which 

 may not be quite adult. The length of Guppy's type is 2.6 mm. and 

 diameter is 1.6 mm. 



Dimensions: Type (U. S. Xat. Mus. Cat. No. 352658) measures: 

 Length 2.7 mm. ; greatest diameter 1.6 mm. 



Occurrence. — Middle or lower Miocene: In flood- wash, Caroni 

 County, Montserrat Ward, 1 mile south of Brasso railway station. 



MARGINELLA (CLOSIA) NITRINA, new species 



Plate 6. fig. 7 



Shell minute, broadly ovate, polished, maximum diameter about 

 four-fifths of the length of the shell and falling a little behind the 

 middle of the vertical axis ; back of body whorl slightly depressed be- 

 low the periphery. Aperture slightly longer than the body whorl 

 both posteriorly and anteriorly, narrow, nearly vertical, expanding 

 a little at either extremity; outer lip with a strong, marginal varix 

 which surrounds the anterior and posterior extremities of the aper- 

 ture and merges with the callus wash over the face of the body whorl ; 

 inner margin coarsely granulose. Columella with four equally 

 spaced, externally papillate plications — anterior two stronger and 

 more oblique, terminal one sharp and marginates the inner wall of 

 the canal. 



Dimensions: Type (U. S. Nat. Mus. No. 352652) measures: Length 

 2 mm. ; greatest diameter 1.5 mm. 



The new species resembles Marginella {Closia) ovuUformis Or- 

 bigny, a species reported from the Pliocene to Recent, but it is a pro- 

 portionately shorter shell with a body whorl anteriorly more acumi- 

 nate and is a more cypraeiform shell than Orbigny's species. 



(9 c<??/r/'enee.— Middle or lower Miocene : In flood-wash, Caroni 

 County, Montserrat Ward, 1 mile south of Brasso. 



MARGINELLA (CLOSIA) LACHRIMULA Gould ? 



Plate 6, fig. 9 



There are two specimens from station 9224, Caroni County, Spring- 

 vale, near Couva, that are somewhat corroded and incapable of exact 

 specific determination. In all characters discernible, they compare 

 with "J/. {Gihherida) lachrimida'^^ Gould,^^ a species that has been 

 reported from the Miocene to Recent, especially abundant in the 

 latter. 



The larger and better preserved specimen (U. S. Nat. Mus. Cat. 

 No. 352655) measures: Altitude 3 mm.; greatest diameter 2.1 mm. 



'^ Boston See. Nat Hist. Proc, vol. 8, p. 281, 1862. 



