1921] NATURAL SCIENCES OF PHILADELPHIA. 323 



Mus., XIX, 1896, p. 306, pi. 27, fig. 9.), seems to resemble closely the 

 young of this species. 



Cythara elongata (Gabb) Plate XVIII, fig. 6. 



Mangelia elongala Gabb, Tr. Am. Philos. Soc. xv, 1873, p. 211; Journ. Acad. 

 Nat. Sci. Phila. 2 Ser., viii, 1881, p. 351, pi. 46, fig. 31, 



This species has 6 ribs, continuous from whorl to whorl. There 

 is a group of faint spiral striae in the region of the anal fasciole, but 

 none elsewhere on the last whorl. Gabb's figure is bad, the last 

 whorl being represented as far too convex. 



Length 7, diam. 2.3 mm. 



The single specimen is no. 2917 A. N. S. P. 



Cythara elevata (Gabb) Plate XVIII, fig. 3. 



Mangdia elevata Gabb, Tr. Am. Philos. Soc. xv, 1873, p. 211. 



This small species has 6| whorls, of which the first 3 comprise the 

 embryonic shell. These whorls are smooth and convex until the 

 last half -whorl, which has close, fine backwardly arched riblets. 

 Subsequent whorls have slightly protractive rounded ribs, eleven 

 on the penult whorl, rather high, and compressed below the sutures; 

 in the lower half of each whorl crossed by three spiral threads, in 

 the intervals of which there are about three very low spirals. On 

 the last whorl there are about 20 major spirals; they are closer anter- 

 iorly, where there are fewer of the low minor spirals, there being 

 four in the upper intervals, down to one in the lower. The aperture 

 is of nearly the same width throughout. Anal sinus rounded. 



Length 6.3, diam. 2.5 mm. ; 7 whorls. 



Type is no. 3224 A. N. S. P. A single specimen. 



Clathurella paupercula (Gabb) Plate XVIII, flg. 4. 



Defrancia paupercula Gabb, Trans. Amer. Philos. Soc. xv, 1873, p. 209. 



The sculpture is of close, small vertical folds which curve back- 

 ward close below the suture, crossed by numerous spiral cords, 7 

 on the penult whorl below the fasciole, one cord above it. The 

 anal sinus is oblique and moderately deep. Lip arches forward, 

 and is strengthened by a rather strong, rounded varix. 



Length 8.5, diam. 3.3 mm., about 4| whorls remain. 



Type no. 2918 A. N.S. P. 



Clathurella gracilis (Gabb) Plate XVI, flg. 10, 11. 



Defrancia gracilis Gabb, Tr. Am. Philos. Soc, xv, 1873, p. 209. 



On the penult whorl there are sixteen axial ribs, crossed by five 

 or six narrow spiral cords ; on the last whorl about eighteen narrow, 

 spiral cords, which are slightly enlarged where they cross the ribs 



