OASTROP01>\ 



Crlntrop>i runulr ) 



:itin^ for the present that I'tfrotheca is a pteropod, we look in vain among 

 the other types of that suit-class of shells for anything corresponding to the triti'l 

 apex of rttmtlicca. We conclude, therefore, that the peculiarity is of generic 

 importance only, and consequently not a serious objection to an arrangement 

 whii-h. in following the suggestion of the other characters, would bring Carinaropsi* 

 atnl rtrrnthfru within the limits of the same order and family. According to our 

 opinion this family will prove to belong to the Docoglossa and not to the Pttropoda. 



CARINAROPSIS OCNUUB Hall. 



PLATE I.XII. FIGS. 10-11. 



OarhiawjHfa (PK>*gmo+mn) cunulit HALL, 1M1, Fourteenth Kept. N. Y. St. Cab. Nat. Hist., p. 94. 



Shell 20 mm. to 25 mm. in width, the length of the largest specimens about 20 

 mm., the bight of the same about 10 mm.; consisting of two or two and one-half 

 volutions, the la-t abruptly expanded. Dorsum angular, or slightly carinated on 

 the .-mall volution, the angle becoming gradually more and more obtuse toward the 

 deeply emarginated anterior edge, where it may be quite obsolete and in some 

 specimens replaced l-y a liroa<l flattened slit-band. Umbilicus small but distinct and 

 deep. Aperture broadly subovate, insinuated in front and somewhat truncated 

 behind; posterior lip reflected. Septum broad, extending about two-fifths across the 

 aperture from the edge of the posterior lip, nearly twice as wide as long, its anterior 

 edge somewhat thickened and slightly arched; behind the edge, which is nearer the 

 plane of the apertural margin than usual, the outer surface is moderately concave. 

 Inner surface of septum distinctly carinate, with a slight continuation of the same 

 feature on the outer side. Inner aperture subtriangular or semi-elliptical, closed 

 by a nearly flat operculum. Surface marked by fine lines and more or less obscure 

 varices of growth. 



This species differs from C. cymbult Hall in having the first volutions larger and 

 projecting farther beyond the posterior lip, which again is more abruptly deflected, 

 t>ut the best difference lies in the septum whose outer surface is much less excavated 

 in this species. 



formation and locality. Vpp?r part of Trenton jtroup, NaahTllle, Tennewee, and Boyle county, 

 Kentucky. 



B.OlUMeh. 



CARINAROPSIS CYMBULA flu/I. 



PLATK I.XII. ill.- I I 



(Pkraymortoma,) cymbtJa HALL, 1861. FmirU-. -nth It-pt. N. V. St. Cab. Nat. IINl.. p. W. 

 (\n error for eymbtOn) HALL, 1862, Fifteenth Kept. H-m., pi. vi. tig*. 12-14. 



Volutions one and a half or two, the first very minute; posterior margin of 



