50 



BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



about one-fourth immersed. Post-nuclear whorls well roundetl, 

 marked b}'" very strong, well raised, almost vertical axial ribs, of which 

 16 occur upon all the whorls of the type. These ribs are strongest 

 in the middle and slightly lower at the summit and peripheiy. 

 Intercostal spaces deeply impressed, equaling the ribs in width, ter- 

 iuinating a very little ])osterior to the suture. Sutures somewhat 

 constricted. Periphery of the last whorl well rounded. Base rather 

 short, well rounded. Entire surface of spire and base marked by 

 fine, wav^% spiral striations. Aperture subquadrate, posterior angle 

 obtuse; outer lip thin, showing the external sculpture within; col- 

 umella short, slender, and oblique. 



The type (Cat. no. 152750, U.S.N.M.) has lost the nucleus and 

 probably the first one and one-half post-nuclear turns; the 12 remain- 

 ing measure: Length 6.7 mm., diameter 1.6 mm. It and another 

 specimen, listed under the same number, were collected in 10 fathoms 

 off San Pedro, California. 



The following specimens have been examined : 



Named for C^harles T. Simpson. 



TURBONILLA (STRIOTURBONILLA i PROFUNDICOLA, new species. 



Plate 3, %^. 11, \Ui. 



Shell elongate-conic, milk-white, shining. Nuclear whorls very 

 small, two and one-half, depressed, helicoid, having their axis at right 

 angles to that of the succeeding turns, in the first of which they are 

 but very slightly immersed. Post-nuclear tiu'ns well rounded, very 

 slightly shouldered at the summit, marked by gently protractively 

 curved, low, rounded, well-developed axial ribs, of w^hich 16 occur 

 upon the first three wdiorls, 18 upon the fourth and fifth, 20 upon the 

 sixth and seventh, 22 upon the eighth and the penultimate turn. 

 Intercostal spaces about one and one-half times as wdde as the ribs, 

 well impressed, terminating about one-tenth of the width of the space 

 between the sutures, posterior to the basal suture, leaving the part 

 anterior between their termination and the basal suture as a plain 



