322 PROCEEDINGS OF THE ACADEMY OF [PaRT II 



Mangilia dominicensis (Gabb) Plate XXXV, flg.l. 



T. (Bela) dominicensis Gabb, Tr. Am. Philos. Soc. x\', 1873, p. 208. 



The type specimen has about 13 axial ribs on the last whorl. 

 Under sufficient magnification it shows close spiral hues of granules, 

 every fourth line slightly larger. On the spire the whorls are strong- 

 ly angular in the middle, but this angle weakens a good deal on the 

 last whorl. 



Length 5.5, diam. 1.75 mm., with 8| whorls, having lost one or 

 two. 



A young specimen in the lot shows 2f convex whorls forming the 

 conic embryonic shell; these seem to be microscopically punctate. 

 They are followed by f of a whorl (nepionic) which is closely sculp- 

 tured with protractive riblets. 



Cythara heptagona (Gabb) Plate XV] I, fig. 9. 



Mangelia heptagona Gabb, Trans. Amer. Philos. Soc. xv, p. 211, 

 Cythara terminula Dall, Trans. Wagner P'ree Inst. Sci.III, pt. 1, 1889 p. 38, 

 Pi. 2, fig. 5. 



After 1 J rounded apical whorls, there is a half whorl having num- 

 erous ribs. On subsequent whorls there are seven narrow, acute 

 axial ribs, continuous from whorl to whorl. Fine, but clearly en- 

 graved spiral lines run over ribs and the broad concave valleys. 

 The outer lip has a longitudinal callus inside beloAV the posterior 

 sinus. 



Length 15, diam. 6.5 mm., 8 whorls. 



The type and another specimen are no. 2915 A. N. S. P. 



Specimens from the Pliocene of the Caloosahatchie River and 

 Shell Creek seem to be specifically identical. They have 7, 8 or 9 

 longitudinal ribs. 



Cythara polygona (Gabb) Plate XVII, fig. 10. 



Mangelia polygona Gabb, Tr. Am. Philos. Soc. xv, 1873, p. 211. 



The first 2 whorls are convex and smooth, the following half whorl 

 multicostate. Following whorls are subangular below the middle, 

 the angulation decreasing gradually to the penult, which is rounded. 

 Last whorl has 15 narrow axial ribs. Spiral striation is fine and close. 



Length 11, diam. 4.4 mm., 7| whorls (type, no. 2916 A. N. S. P.). 



Other specimens of the type lot show varying numbers of ribs, 

 from 1 1 to 18 on the last whorl. When numerous, the ribs are not 

 continuous from whorl to whorl throughout. Another specimen 

 is labelled Cibao Valley. 



C. gibba Guppy, from the Oligocene of Jamaica (Proc. U. S. Nat. 



