1921] NATURAL SCIENCES OF PHILADELPHIA. 397 



cords are distinctly beaded by retractive grooves, but the beading 

 is weaker on the last whorl. The flat base has about 12 small 

 smooth cords. 



Alt. 5, diam. 4.6 mm., 6 whorls. 



Type is no. 2821 A. N. S. P. One specimen. 



Solariella (?) tricarinata (Gabb) Text-flg. 33, 



Margarita tricarinata Gabb, Tr. Amer. Philos. Soc, xv, p. 24.3. 



This minute shell has three strong coarinae in ^^/C^^XX 



the peripheral region and rounded beads be- ^' _..^.. 



low the suture and on the umbilical angle. (TT.- --^-."^.^■I^^^ ^-^—^ 



There are some short radial folds external to xr" f^B^X 



the latter. The initial 1| whoHs are smooth ^^ \^^WJ 



and rounded. It is obviously a very young . ^ — ^""^ 



shell and possibly belongs to Liotia. tricarinata. " ^^^^ " 



Alt. 1.15, diam. 1.4 mm.; 3 whorls. 



Type is no. 2836 A. N. S. P. 



CYCLOSTREMATIDAE. 



Circulus pentagona (Gabb) 



Vitrinella pentagona Gabb, Trans. Amer. Philos. Soc, xv, 1873, p. 243; Journ. 

 Acad. N. S. Phila. viii, p. 368, pi. 47, fig. 68. 



This species resembles C. trilix (Bush), but is much smaller. The 

 unique type measures, alt. 0.9, diam. 1.9 mm.; 3f whorls. The 

 front part of the last whorl is broken, but shown restored in Gabb 's 

 figure. 



Type no. 2831 A. N. S. P. 



Circulus domingensis Pils. and Johns. Plate XXXVII, figs. 6, 6a, 7. 



Proc. A. N. S. Phila., 1917, p. 184. 



In a smaller, more perfect specimen found among Gabb's du- 

 plicates, there are more numerous, smaller spirals within the umbilicus 

 (Plate XXXVII, fig. 7). In the type the ribs are worn on the peri- 

 phery, hence appear weaker in the figure than in perfect specimens. 



Vitrinella (Episcynia) naso (Pils. and Johns.) Plate XXXVII, figs. 5, 5a. 

 Discopsis (?) naso Pils. and Johns., Proc. A. N. S. Phila. 1917, p. 184. 



Adeorbis carinata Gabb is thought by Dall to be "probably iden- 

 tical with Vitrinella (Episcynia) inornata Orb." (Trans. Wagner 

 Inst. Ill, 420). This note was overlooked at the time we redescribed 

 the form in 1917. While it is apparently related to that recent spe- 

 cies (which we know only by Orbigny's account and figures), we con- 

 sider it specifically distinct. 



