ART. 22 MIOCENE GASTROPODS AND SCAPHOPODS MANSFIELD 43 



posterior one strongest and the following ones gradually diminish- 

 ing in size. 



Dimensions: Figured specimen (Cat. No. U. S. Nat. Mus. 352659) 

 measures: Length 55 mm.; greatest diameter 15 mm. 



Locality figured specimen: 9195. Caroni County, Couva Ward, 

 Springvale, near Couva. J, A. Bullbrook, collector. 



The nature of the sculpture of the variety differs from both 

 that of Mitra henekeni and Mitra longa Gabb. It has more folds on 

 the columella than M. henekeni. Perhaps it is closer related to M. 

 longa than M. henekem., but it is a much stouter shell than that 

 species. 



Occwn'ence. — Upper Miocene: " Savanetta " (Guppy), U. S. Nat. 

 Mus. Cat. No. 11595, labeled " Mitra henekeni Sow." 



Genus VEXILLUM Bolten 



VEXILLUM BRISTOLI (Maury) 



Plate 8, fig. 2 



l^urriciiki bristoli Mairy. Bull. Auier. Paleoiit., vol. 10, no. 42, p. 205, pi. 35, 

 fig. 5, 1925. 



Shell subfusiform, solid, moderately stout, turrited, last whorl a 

 little longer than spire, with one and one-half nuclear and six post- 

 nuclear whorls. Nucleus smooth, apical turn small, succeeding one 

 slightly inflated and much larger. Postnuclear whorls gradually 

 enlarging, shouldered adjacent to and below the distinct suture. 

 Axially sculptured with about fourteen nearly vertical, rounded and 

 smooth ribs, extending from suture to suture over the spire whorls 

 and continuing w^eaker over the canal on the last whorl. Spirally 

 sculptured with impressed lines (six on penult whorl) lying in the 

 interaxial valleys, separated by square-topped interspaces of about 

 equal width. Over the canal, three to four spirals are wider spaced 

 and stand out in relief. Aperture rather narrow. Canal short. 

 Outer lip sculptured within with seven slender, keeled, spiral lines. 

 Columella "with four plications, beginning a little above the center 

 of the aperture, successively diminishing in size anteriorly. A sin- 

 gle plication is on the body wall just below the commissure of the 

 outer lip. 



Dimensions: Figured specimen (U. S. Nat. Mus. Cat. No. 352660) 

 measures: Altitude 7.5 mm.; greatest diameter 2.6 mm.; length of 

 aperture 3 mm. 



The species is a smaller, stouter, and more turrited shell than the 

 species Vexillum tortuoselhi/m (Pilsbry and Johnson) described from 

 the Dominican Republic. 



