349 Costa Rica Miockne — Olsson 77 



rounded beds or tubercles; immediately after the nucleus, there 

 is but one spiral, soon followed by two and on the penultimate 

 there are three; the last whorl has five spirals and three or four 

 more on the canal; aperture elliptical with a large expanded out- 

 er lip, smooth within and a deep, anal sinus at its upper end; 

 canal short and straight. 



Height 5.75, diameter 2.75, last whorl 3.75 mm. 



A small species doubtfully referred to Glyphostoma, having 

 the outer lip smooth within and lacking the peculair, submicro- 

 scopic structure of typical Glyphostoma. 



Its sculpture is coarse, the intersection of the ribs and spirals 

 forming small beads or tubercles. 



Gatun Stage: Port Linio7i. 



Genus CYTHARA Schumacher 

 Cythara terminula var. costaricensis, n. var. Plate 5, figures 21, 22 



cf. Cythara terminula Dall, 1890, Trans. Wagner Free Inst. Sci., vol. 

 3, pt. 1, p. 38, pi. 2, fig. 5. 



The Cythara terminula Dall, to which the present shell ap- 

 pears closely related, was described from the Caloosahatchie 

 beds of Florida, of Pliocene age. The Costa Rican shell with 

 the same number of whorls is somewhat small (typi- 

 cal terminula of 7 whorls, 16 mm), (variety costaricensis 7 or 8 

 Vv'horls, 13 mm), and has 8 instead of 9 ribs. The details of the 

 spiral sculpturing is very similiar, consisting of flattened bands 

 separated by sharp channels. The spiral bands carry a central 

 incised line, which produce the appearance of being in pairs. 



C. cercadica Maury from Santo Domingo, is a larger species 

 with higher spire and simple and not banded spirals. 

 Length 13, diameter 5, last whorl 10 mm. 



Gatun Stage: Hill la. Banana River. 



CytharelSa limata, n. sp. Plate 5, figure 20 



Shell small, nearly smooth and porcellaneous; spire slightly 



