1899.] NATURAL SCIENCES OF PHILADELPHIA. 165 



Turbonilla unilirata, new species. Plate VIII, fig. 6. 



Shell small, very slender, gradually tapered, dead white 

 (weather worn), without incised, spiral lines on the intercostal 

 spaces and base. Whorls very slightly convex, 9, in the largest 

 example, below the small nucleus, which is transverse to the axis, 

 with very projecting whorls. Suture deep and straight. Trans- 

 verse ribs narrow, rounded, slightly oblique, inclined to the left, 

 varying from 20-24, with wider, deep, flattened interspaces ending 

 at the periphery of the body-whorl with deeper, square-cut ends. 

 The interspaces are crossed by a single, conspicuous, raised, spiral 

 thread or lira, a little below the sutures. Base rounded, smooth. 

 Aperture somewhat elongate ; pillar-lip straight, thin and slightly 

 reflected. In some of the examples the outer-lip is broken, reveal- 

 ing a spiral, tooth -like ridge on the columella. 



Length of the type, 3 mm. ; diameter, | mm. ; length of aper- 

 ture, about 4 mm. A larger specimen is 3^ ram. long and about 

 ^ mm. wide. 



Four specimens (No. 79,010) from St. Thomas, W. I., aud a 

 single worn, imperfect specimen, dredged by the U. S. Fish Com- 

 mission, in 1884, off" Cape Hatteras, K C, at station 2,277, in 16 

 fathoms. 



This species was labelled as T. pusilla C. B. Adams, 1850 (not 

 Philippi, 1844), and appears to be the one figured by Try on 

 {Manual, PI. 76, fig. 19) as an example of that species. 

 Turbonilla Penistoni, new species.. PI. VIII, fig. 14. 



Turbonilla pulchella Heilprin, The Bermudas, p. 173, 1889. 



Shell white, exceedingly slender, gradually tapered, semitrans- 

 parent, lustrous. Whorls moderately convex, 11, below the small 

 nucleus of 2^ very projecting whorls, transverse to the axis. Su- 

 ture deep. Transverse ribs about 15 (the specimen has been injured) 

 stout, rounded, oblique, slightly sigmoid, separated by about 

 equally wide, deep spaces which terminate at the periphery of the 

 well-rounded body-whorl with square-cut ends. Base rounded,, 

 smooth. Aperture somewhat elongated, Avith the pillar-lip straight, 

 moderately tliickened, reflected and forming a decided angle at its 

 juncture with the thin outer-lip. Under the microscope the entire 

 surface is covered with very fine, spii*al stride. 

 ' Length, 4^ mm. ; diameter, 1 mm. ; length of aperture, about 

 1 mm. 



