78 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



TURBONILLA (PYRGISCUS) OBESA, new species. 

 Plate 7, figs. 3, 3a. 



Shell robust, chocolate brown. Nuclear whorls small, deeply 

 obliquely immersed in the first post-nuclear turn, above which only the 

 tilted edge of the last one projects. Post-nuclear whorls flattened, 

 moderately shouldered at the summit, marked by strong vertical 

 axial ribs, which are decidedly contracted at their junctions with the 

 spiral grooves, which lends them a somewhat nodulous aspect. Of 

 these ribs, 16 appear on the first, 18 on the second, 20 upon the third 

 to fifth, 22 on the sixth, and 24 on the penultimate turn. Intercostal 

 spaces about as broad as the ribs, crossed by five strongly incised 

 spiral grooves which almost cross the ribs. One of tliese is at the 

 periphery. The remaining four appear in a double series; the one 

 placed about as far below the summit as the other is above the periph- 

 ery, the space between them being wider than that between the 

 summit and the first pit below it. Two fine incised spiral lines mark 

 the space between the summit and the first series of pits below it. 

 Periphery of the last whorl marked b}^ a broad plain band, well 

 rounded. Base very short, well rounded, marked by about six un- 

 equal and unequally spaced strong incised lines. Aperture pear- 

 shaped; posterior angle acute; outer lip thin, showing the external 

 sculpture within; columella oblique, slightly revolute, provided with 

 a moderately strong fold at its insertion. 



The type (Cat. no. 16256.3 U.S.N.M.) was collected at Pacific Beach, 

 California. It has eight post-nuclear whorls, and measures: Length 

 5.2 mm., diameter l.S mm. 



TURBONILLA (PYRGISCUS) FA VILLA, new name. 



Chemnitzia coelata Carpenter, Ann. Mag. Nat. Hist., 3d ser., vol. 15, 1865, p. 

 400, not Chemnitzia coelata Gould, Proc. Bost. Soc. Nat. Hist., vol. 3, 1861, 

 p. 406. 



"Shell quite large, elongate, ashy. (Nuclear whorls decollated.) 

 Post-nuclear whorls 13, flattened, separated by weakly impressed 

 sutures. Axial ribs 20 to 28, straight, subacute, suddenly truncated 

 at the peripherv. Intercostal spaces marked by 4 to 5 deeply im- 

 pressed spiral grooves, which pass up on the sides of the ribs but do 

 not cross their summits. Periphery of the last whorl angulated. 

 Base short, marked by 6 spiral lines. Aperture subquadrate; col- 

 umella strongly twisted. Length 8.8 mm., diameter 2.3 mm." 



The above is Doctor Carpenter's description, to which he adds: 

 "This beautiful and imique shell was probably from Panama; but 

 there was no locality mark. It is remarkable for its deep furrow and 

 the suddenly shortened and spirally sculptured base. It is much 

 larger and broader than the northern C. virgo, and differs in details of 

 sculpture." We have not seen tliis species. 



