FRESH WATER AND LAM) SHELLS. *) 1 



Remarks. — Among the seven specimens before me there is a good deal of difference. 



Some arc darker than others. Several have the superior portion of the whorl rising into 

 a ridge, quite nodose, while others are entirely without it. This species has more resem- 

 blance to M. Haysiana than any other which has come under my notice. It is not, how- 

 ever, so elliptical a shell, and the aperture is shorter. The aperture of the arciata is 

 rather more than one-third the length of the shell; is obtusely anguUfr below, and some- 

 what acutely angular above, where it is thickened. 



M LLAMA CREBRI-STIUATA. PI. IX. Fig. 47. 



Testa transverse et crebrissime striata, subfusiformi, crassd, luteo-corned ; spird obtusa ; suturis impressis; 

 anfraclibas subconvcxis; uperlurd pared, subovatd, ad basim angulatd, intus albidd; columella injlccta superne 

 incrassald. 



Shell transversely and very closely striate, nearly fusiform, thick, yellowish horn-colour; spire obtuse; sutures 

 impressed ; whorls somewhat convex; aperture small, rather ovate, angular at the base, within whitish; columella 

 inflected and thickened above. 



I lab. Tuscaloosa, Alabama. B. W. Hudd, M. D. 



My cabinet and cabinet of Dr. Budd. 

 Diam. .40, Length .7G of an inch. 



Remarks. — This species is nearly allied to M. impressa, (Nobis,) but may be distin- 

 guished by its colour being yellowish, and by its coarser stria). Its aperture also is 

 smaller. The three specimens before me are very differently banded, one having nine, 

 another three, and the last a rather broad one near the upper part of the whorl. These 

 arc only seen on the inside. The apex of each being eroded, the number of the whorls 

 could not be accurately counted. Perhaps there are six. The stria) arc so strong that 

 the] cause the edge of the outer lip to be crenate. The aperture is about two-fifths 

 the length of the .-hell. On the superior whorls there are broad, slightly elevated, some- 

 what oblique ribs. The number of striae on the three specimens before me are, re- 

 spectively, sixtet n. eighteen, and twenty. 



M ei. am a nobilis. PI. IX. Pig. 48. 



Testa tuberculoid, conoided, suberassd, htteo-corned ; spird devoid; suturis irregulariter undulatis; anfrac- 

 tibus plannlatis.ia medio tuberculatis : aperturd subgrandi, producta, ad basim angulatd et cana/iculatd, intus 

 luted; columella torta. 



- 11 tnherculate, conical, ratln-r thick, yellowish horn-colour; spire elevated; sutures irregularly undulate ; 

 whorls flattened, in the middle tuberculate; aperture rather large, elongated, angular, and channelled at the base, 

 within yellowish; columella twisted. 



Hab. Alabama. Major Lo Contc. 

 Cabinet of Major Le Contc. 

 Diam. .7,\ Length 1.7 inches. 



Remarks. — This is among the finesl of our American Bpecies. It is remarkable for its 



large size and extended sinus, which allies it to the genus /". in winch it might, with no 

 great impropriety, be placed. The specimen before me has eight whorls, and the broken 



