ART. 22 MIOCENE GASTROPODS AND SCAPHOPODS MANSFIELD 15 



suture to suture, and much jfiner spirals overrunning the axials anrl 

 situated on the anterior third of the whorl. Postnuclear whorls 

 with a wide, rounded-bottomed sulcus behind the suture and another 

 narrower sulcus at the posterior third of the whorl. Spiral sculp- 

 ture consists of a prominent, sharp, smooth ridge, adjacent and an- 

 terior to the suture, and two strong cords overrunning the ribs on 

 the anterior half of the whorl; besides these, there is a single spiral 

 thread just in front of the suture, two in the sulcus behind the ribs 

 and a stronger and sharper one in front of the ribs. Axial sculpture 

 consists of many, weakly nodular ribs occupying the anterior half 

 of the whorl, and many, evidently growth lines, retractive over the 

 posterior part of the Avhorl and mainly protractive over the anterior 

 part. The base and pillar are sculptured Avith spiral cords and 

 close-set groAvth lines. Outer lip broken away at the margin, within 

 there are six sharp spiral threads extending nearly to the margin. 

 Anterior part of canal broken off. Columella smooth, covered with 

 callus. 



The description is made from two specimens, a larger specimen 

 showing the nature of the sculpture and a smaller specimen possess- 

 ing a well preserved protoconch. 



Dimensions of the larger cotype (U. S. Xat. Mus. Cat. No. 352626) : 

 Length 16 mm. ; greatest diameter 6 mm. 



Type locality: Station 9212. In flood-wash, one mile south of 

 Brasso, Trinidad, British West Indies. 



J. A. Bullbrook, collector. 



The new species here described is similar to Pleurotoma ponto- 

 netisis Dall (Ms.) from Ponton, Santo Domingo, but the latter 

 species possesses a different type of nucleus, a more excavated sulcus 

 behind the ribs and more fine sjDirals in front of the carinate spiral 

 just anterior to the suture. 



The nature of the sculpture is very similar to a new unpublished 

 species from the Shoal River marl member of the Alum Bluff for- 

 mation, Florida. The described species is also related to Pleurotoma 

 {GemmuJa) imningeni Brown and Pilsbry '^ from the Gatun forma- 

 tion. Panama. The latter species has a smaller apical angle and 

 apparently lacks the paired spiral cords over the ribs. 



DnUki vaningeni var. sancti andrae Maury ' is related to the new 

 species and may prove to be a very closely related species when 

 complete forms are obtained. 



Occu'iTence. — Middle or lower Miocene : 8302. 



TURKIS VANINGENI var. MACHAPOORENSIS (Maury) 



Drillia vaningeni var. machrapoorevsis Maury, Bull. Amer. Paleont.. vol. 10, 

 no. 42, p. 191, pi. 32, figs. 5, 9, 1925. 

 Occurrence. — Middle or lower Miocene : station 9219. 



"Acad. Xat. Sci. I'hila. l-roc, vol. (jt, p. 50.5, pi. 22, tig. 4, 1913. 



' Bull. Amer. Paleont., vol. 10, no. 42, p. 191, pi. 32, figs. 1, 14, 1925. 



