THE BAHAMA ISLANDS 33 



Cepolis (Hemitrochus) tkoscheli Pfeiffer. 

 Helix troscheli Pfeiffer, 1846, Symb. ad. hist. Hel., Ill, p. 76; Conch. Cab. ed. II, 



Helix, pi. 109, figs. 6-11. 



Fossil in the quarry of aeolian rock on top of Nassau ridge, Nassau, New 

 Providence Island, at Station 15. Living at New Providence, Gun Cay and 

 Tnagua Island. 



This species agrees well with the recent shell with which we have iden- 

 tified it. 



Cepolis (Plagioptycha) pharcida n. sp.' 

 Plate XII, Figs. 2, 3. 



Fossil at Station 19, in seolian rock on the east side of Eum Cay. 



Shell depressed, thin, originally yellowish with a pale peripheral band, 

 five whorled; spire depressed conic, whorls above slightly convex with a well- 

 marked suture; nuclear whorls smooth, polished, later ones with fine, close 

 threadlike sculpture following the incremental lines; periphery of the last 

 whorl a little above the middle of the whorl and slightly prominent though 

 rounded; base rounded, umbilicus small, deep; termination of the adult last 

 whorl bent down, constricted, then expanded and below a little reflected, 

 broad at the very short pillar, narrow above, with a fold or ridge projecting 

 into the lumen of the whorl behind and parallel with the basal lip ; the plane 

 of the aperture forming an angle of about 45° with the vertical axis of the 

 shell. Height 10, major diameter 19, minor diameter 15.5 mm. 



This species is nearest to C. gregoriana Dall. Than C. duclosiana it is 

 smaller, smoother, more polished and with the gular fold shorter, higher, and 

 more obliquely set with regard to the lip in front of it. The sculpture of 

 the present species is more like that of the Haitian Cepolis than that of most 

 of the living Bahama Plagioptycha. The fossil species is the largest of 

 the group to which it belongs, and recalls the Oligocene Cepolis instrumosa 

 Dall, of the Tampa, Florida, silex beds, more than any of the recent species. 



Cerion (Strophiops) agassizii Dall. 

 Plate XII, Fig. 5. 



Cerion (Maynardia) agassizii Dall, 1894, Bull. Mus. Comp. Zool., XXV, No. 9, p. 120. 

 figs. 9, 10. 



Fossil in the seolian rock of the quarry at the top of Nassau ridge, 



Nassau, N. P., at Stations 9 and 15, and in the cpiarry back of the hospital 



grounds, Nassau, at Station 17. 



