416 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.39. 



wliorls the median cord is almost completely lost, while the one 

 above the sutural hne retains its strength. On these tliree whorls 

 additional fine spiral lines make their appearance. The axial sculp- 

 ture consists of fine lines of growth only. Sutures weakly channeled. 

 Periphery and base of the last whorl well rounded, marked by eight 

 subequal and subequally spaced, spiral keels and fine lines of growth. 

 The space immediately surrounding the umbihcal area has no spiral 

 sculpture. Aperture broadly ovate; posterior angle obtuse; outer 

 lip thin; columella slender, decidedly curved and slightly reflected 

 over the narrow umbiUcus; parietal wall glazed with a thin callus. 



Doctor Carpenter's type (Cat. no. 40933, U.S.N.M.) was collected 

 by Dr. J. G. Cooper at San Diego, California. It has 9 post-nuclear 

 whorls and measures: Length 7.2 mm., diameter 2.4 mm. Two 

 additional lots are in the U.S.N.M., Cat. no. 195218 (1 specimen) 

 from San Pedro, California, and Cat. no. 160095a (1 specimen) from 

 San Diego, California. 



ALABINA TENUISCULPTA DIEGENSIS, new subspecies. 

 Plate 61, fig. 4. 



Shell elongate-conic, chestnut brown, excepting the extreme apex 

 and the last volution, which are paler. Nuclear, whorls 3, small, 

 increasing regularly in size, well rounded, without sculpture. The 

 early post-nuclear whorls have a decidedly sloping shoulder which 

 extends from the middle to the whorls, between the sutures to the 

 summit. This shoulder is marked on the first v/horl by a single cord 

 that limits it anteriorly, on the second by an additional cord, which 

 divides the shoulder in two equal halves, while on the third, two 

 additional cords a little less strong than the other two divide the 

 space between the summit and the first cord, and the space between 

 the next two cords into equal halves. The sculpture on the anterior 

 half of the whorls between the suture consists of a single cord on the 

 first and second, which is halfway between the median cord and the 

 suture. On the third, an additional cord a little less strong appears 

 between the two. This cord becomes equal in strength to the other 

 two on the succeeding turns. The space between the suture and the 

 first supra-sutural cord remains plain, barring exceedingly fine 

 microscopic spiral striations and is as wide as the space between this 

 cord and the median cord. In addition to the spiral sculpture, the 

 whorls are marked by very many irregular decidedly curved and | 

 regularly distributed axial riblets, which render their intersections | 

 with the spiral cords very weakly nodulose. The summits of the 

 whorls are roundly shouldered and make the sutures appear con- 

 stricted. Periphery and base of the last whorl somewhat inflated, 

 well rounded, the latter marked by seven equal and equally spaced, 

 low, rounded, spiral cords and feeble axial threads. The space 



