128 BUL1.ETIN 39 300 



tured body-whorl and a long attenuated spire; whorls 6 plus 

 (apex broken so that at least one complete whorl is lost from the 

 type specimen); the first 4 whorls are smooth, after which a 

 few incised spiral lines appear just below the upper suture; these 

 spirals gradually increase in strength and in number and on the 

 following whorls have become strong, raised spiral cords; the pen- 

 ultimate whorl has 5 spirals, the last about 24 (including those 

 of the anterior canal) ; the upper half of the last whorl and some- 

 times the penultimate, are longitudinally plicated with 18 rib-like 

 costae; aperture narrow, with a thickened outer lip, notched 

 above and obsoletely denticulated below; the inner lip is smooth; 

 canal short, tvdsted. 



Length 16, diameter 8.5, aperture 9, spire 7 mm. 



An unusually short and broad species, distantl}^ related to 

 the C. pulcherrima Sowerby, recent from the Gulf of Dulce. Two 

 specimens were collected from the Gatun sandstones of Water 

 Oay. 



Gatun Stage: Water Cay. 



StromSjina costaricerisis, n. sp. Plate 10, figures 8, 17 



Shell solid, ovate, with a long attenuated spire; last w^horl, 

 large, flattened or contracted about the middle; whorls about 9^^; 

 the first 6 whorls are smooth and form the long attenuated spire; 

 faint longitudinal plicae appear on the 7th, which increase in size 

 and form the rib-like costal on the later whorls; axial ribs persist- 

 ent and number on the last whorl about 15; the spirals begin 

 shortly after the first appearance of the longitudinal plicae as 

 faint incised lines near the upper suture; these spiral lines are 

 further increased by the introduction of more lines below and be- 

 come on the following whorls raised spiral cords; the penulti- 

 mate whorl has 5 or 6 spirals, the last with about 20; the spirals 

 vary in strength on individual shells and on some specimens may 

 be lacking from the middle of the whorl, forming a smooth me- 

 dian band; aperture linear, small and contracted and with a cal- 

 loused inner and outer lip ; outer lip strongly thickened, notched 

 above and feebly dunticulated below; canal short, straight. 



