356 LAND AND FRESH-WATER SHELLS OF N. A. [PART IV. 



3. S. ovoidemn, Shuttleworth. 



Gyrotoma ovoideum, Shuttleworth, Mittheil, Bern. Nat. Gesell., No. 50, p. 88, 

 July -11, 1845. H. & A. Adams, Genera, iii, t. 32, f. 4. 



Description. — Shell conoidal, thick, olivaceous, concentrically stri- 

 ng. 673 ate-costate, brown -baudod, apex eroded; whorls about 

 five, thickened at the suture ; fissure very narrow, elon- 

 gate; columella thickened above. 



Length, about -7; breadth, •4--4i of an inch. Length 

 of aperture, -3 of an inch. Length of fissure, -2 of an 

 inch. 



Observations. — Closely approaching Melania olivula, Con- 

 rad, in form; varied by confluent bands. — Shuttleworth. 



Figured from H. and A. Adams, "Genera." It appears to 

 be a more cylindrical and narrower species tlian the following. 



4. S. excisum, Lea. 



Melania excisa, Lea, Philos. Proc, p. 242, Dec, 1842. Philos. Trans., ix, 1846. 



Jay, Cat., 4th edit., p. 273. 

 Schizostoma excisa, Lea, Wjieatlet, Cat. Shells U. S., p. 28. 

 Oyrotoma excisa, Lea, Binney, Check List, No - 317. Brot, List, p. 27. Lea, 



Adams, Genera, i, p. 305. 

 Melatoma excisum, Lea, Reeve, Monog., sp. 2. 



Description. — Shell striate, subfusiform, rather thick, yellowish ; 

 spire ovately conical ; sutures impressed; whorls flattened ; aperture 

 cut out above, small, elliptical, white. 



Habitat. — Alabama. 



Diameter, -40 ; length, -64 of an inch. 



Observations. — This shell is very remarkable for the cut in the 

 superior part of the outer lip, very similar to some species of Plezi- 



rotoma. This cut extends nearly one-fifth round the 



Fig. 674. Fig. 675. 

 whorl, leaving immediately below the suture an ele- 

 vated ridge. There are nearly three whorls of this 

 specimen perfect, and the cicatrix shows the cut to 

 have extended in due proportion thus far. The ap- 

 erture is rather small, and rather more than one- 

 third the length of the shell. On the spire there is a slight dispo- 

 sition to plication. The apex being eroded, the number of whorls is 

 not certain, perhaps six. This specimen has three revolving, pui'ple 

 bauds. — Lea. 



