76 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



Base with spiral sculpture — Continued. 



Axial ribs extend over the base to the umbilical area — Continued. 

 Base of the last whorl not decidedly inflated. 



Shell very large, adult more than 13 mm cnstaneUa, p. 102. 



Shell less than 10 mm. 



Incised spiral lines between the sutures of uniform strength. 



Whorls strongly shouldered indentata, p. 102. 



Whorls not strongly shouldered. 



Incised spirals between the sutures 3 .cora, p. 103. 



Incised spirals between the sutures 7. 



Axial ribs 14-22 craticulata, p. 104. 



Axial ribs 3o-40 cemlva, p. 104. 



Incised spirals between the sutures 8, or 8 on the early turns 

 and 10 on the later ones. 



Basal striations 5 Icpta, p. 105. 



Basal striations 12 histias, p. 105. 



Incised spirals between the sutures 9 subula, p. 106. 



Incised spiral lines between the sutures not of uniform strength. 

 Incised lines between the sutures all strong. 



Shell large, adult more than 8 mm. long wickhami, p. 106. 



Shell small, adult less than 6 mm. long. 



Incised spiral lines between sutures 9 lara, p. 107. 



Incised spirals between the sutures consisting of strongly impressed 

 pits or lines and fine striations. 



Spiral pits 2, one peripheral and one median, fine lines 28. 



cinctella, p. 108. 



Spiral pits 5, fine lines 5 adusta, p. 108. 



Spiral pits 7, fine lines 4 larunda, p. 109. 



TURBONILLA (PYRGISCUS) ANNETT.a;, new species. 

 Plate 7, fig. 7. 



Shell very thin and delicate, yellowish-white. (Nuclear whorls 

 decollated.) Post-nuclear whorls concave with a tuberculated 

 shoulder a little below the summit, marked by strong, sinuous, slender, 

 almost vertical axial ribs, of wdiich 18 occur upon all but the penulti- 

 mate w^horl, the latter having 20. Intercostal spaces about four 

 times as wide as the ribs, marked by seven broad, incised, spiral pits. 

 The space between the first and second pit below the summit forms a 

 rather strong raised spiral cord, the junction of which with the ribs 

 renders them tuberculate. Periphery of the last whorl angulated. 

 Base well rounded, marked by the feeble continuations of the axial 

 ribs only. Aperture rhomboidal; posterior angle acute; outer lip 

 thin, showing the external markings within ; columella slender, curved 

 and slightly revolute. 



The type (Cat. no. 163265, U.S.N.M.) and another specimen were 

 dredged at U. S. Bureau of Fisheries station 2792 in 401 fathoms, off 

 Manta, Ecuador. 



The type has the last six and one-half whorls and measures: 

 Length 3.7 mm., diameter 1.3 mm. 



