FEOM PLIOCENE CLAY BEDS IN COSTA RICA. 351 



METULA, H. and A. Ad. 



M. CANCELLATA, Gabb, PI; 46, fig. 32. 



id.^ Gabb, Memoir on Sto. Domingo, Tr. Amer. Philos. Soc.jlSTS. 



A rare shell in Santo Domingo, whence it was described, it appears here also 

 very rare. It has not been yet found living. 



DRILLIA, Gray. 

 D. MoENENSis, Gabb, n. s., PL 46, fig. 33. 



Shell small, robust ; spire elevated, longer than the aperture ; whorls eight-and- 

 a-half, the upper two-and-a-half being nuclear ; suture well marked and bordered 

 on the succeeding whorl by a small rib. Surface ornamented by about eight heavy 

 longitudinal ribs, which barely reach the suture above, and fade out on the body 

 whorl, in front. These are crossed, besides the one thread-like rib bordering the 

 suture, by half-a-dozen similar ribs, three of which are visible on the upper volu- 

 tions. Directly below the rib bordering the suture, and extending to the shoulder 

 of the whorl, is a space not ribbed, and which corresponds to the sinus of the lip. 

 With a magnifying glass, between the revolving ribs can be seen numerous others, 

 very minute, and which, being crossed by the lines of growth of about equal size, 

 present a finely woven appearance. Aperture contracted, canal short ; inner lip 

 heavily encrusted ; outer lip thickened ; posterior sinus well marked, but not deep. 



Figure. Magnified four times natural length. 



But two specimens, from the " deep cut," near Moen. 



MANGELIA, Leach. 



M. ELONGATA, Gabb, PI. 46, fig. 34, 

 id.^ Tr. Amer. Phil. Soc, v. 15. 



Described from the Miocene of Santo Domingo; now found near Moen. The 

 specimen figured is the original from Santo Domingo, from which the description 

 was made. The Costa E.ican agrees in every respect. 



M. SUBCYLINDRICA, Gabb, n. s., PL 46, fig. 35. 



Shell small, subcylindrical, body whorl constituting about half the length of 

 the shell ; spire composed of six whorls, the upper two nuclear and smooth ; 

 whorls sloping in so rapidly at the top to the suture as almost to merit the term 

 truncated. Surface ornamented by even, large longitudinal ribs, about nine to a 

 volution, and with deep interspaces ; all crossed by numerous small revolving ribs, 

 between which are microscopic revolving lines. Aperture narrow ; posterior sinus 

 narrow, deep, and round • outer lip thickened. 



