FROM THE TERTIARY OF VIRGINIA. 267 



naked eye. The base is smooth, with the exception of two or three small striae, imme- 

 diately below the periphery of the whorl. As my only specimen is imperfect, I am 

 unable to determine the dimensions or number of whorls. 



The smooth base and peculiar rounded columella distinguish this shell from our other 

 tuberculated fossil Trochi, some of which it much resembles. 



This pretty little shell was sent to my father from the neighbourhood of Petersburg 

 by E. Ruffin, Esq., whose name I have great pleasure in affixing to it as a slight token 

 of respect for his zeal in elucidating the Geology of Virginia. 



GENUS TURBO. 

 T. GLABER, PL. 37. FIG. 87. 



T. testa ovalo-turbinatd, elevald, tenui : umbiltcatd, l&vi, nitente; spird elevatd, rotundatd; suturis parvis, linearibusj 



anfractibus ., valde convexis; anfractu ultimo rotundato; basi Icevij umbilico parvo; aperturd ovatd } superne angu- 



latd } inferne rotundatd; labro acuto. 



Shell ovately turbinate, elevated, thin, umbilicate, smooth, polished; spire elevated, rounded; sutures small, linear; 



whorls , very convex; last whorl rounded; base smooth, umbilicus small; mouth ovate, angular above, rounded 



below; outer lip acule. 



Length . Breadth .80 of an inch. 



Remarks. The umbilicus is small, and partially covered by an extension of the co- 

 lumella. The surface of the shell is glabrous, but not perfectly smooth, owing to ine- 

 qualities in the growth, with occasional faint longitudinal lines. The mouth has a small 

 internal channel-like impression where it meets the preceding whorl. 



Having but one specimen of this shell, and that imperfect at the apex, I am unable to 

 give its length or number of whorls. Of the latter, a little more than two remain, and 

 about two or three must have been removed. 



This shell bears so strong a resemblance to the recent Paludina vivipara, Auct., that 

 were it not found among oceanic shells, I should have little hesitation in considering it as 

 a variety of that species. 



This shell is by far the largest of the genus as yet discovered in our Tertiary. It is 

 unusually elevated in the spire for a Turbo. 



T. RUSTICUS, PL. 37. FIG. 88. 



T. testa globoso-conica, crassd, perforatd, cancellatd; spira conicd, depressd, acutd; suturis parvis, linearibus; an- 

 fractibus quinque, planulatis; striis transversis crebris, magnis; striis longitudinalibus crebris, parvis; anfractu 

 ultimo rotundato; basi striatd transverse et alternatim; perforatione parvd, angustd; aperturd quadrato-rotundatd. 



Shell globose] y conical, thick, perforate, cancellate; spire conical, depressed, acute; sutures small, linear; whorla 

 five, flattened; transverse striae numerous, large; longitudinal striae numerous, small; last whorl rounded; base striate 

 transversely and alternately; umbilicus small, narrow; mouth quadrately rounded. 



Length .12. Breadth .11 of an inch. 



Remarks. The transverse strise on the upper part of the last whorl show a slight 

 disposition to be alternate, and on the base they become entirely so. The whorls are 

 sub-canaliculate at the upper sutures. The columella has a very slight incrassation at 

 the base, but not sufficient to constitute the shell a Monadonta. The mouth is angular 

 at the upper part of the columella, and round at the outer lip. 



