NEW MELANIDiE OF THE UNITED STATES. 255 



it has much resemblance to the rounded varieties of that protean species, prcerosa, 

 Say, it may be distinguished by its being still more globose than its most globose va- 

 rieties, by its delicacy, smoothness and brilliancy. Dr. S. says in his letter that he 

 thinks it decidedly distinct from all others he has out of many thousands, and that " it 

 is more rotund than any other." The largest specimen is four fifths of an inch long, 

 has four well-marked continuous bands, with rows of maculation between them. The 

 middle-aged specimen is quite saffron, has the same number of bands with the rows 

 of maculation, but these bands are somewhat broken up, and the maculations are not 

 so regular. In the third, the youngest one, the maculations are almost entirely ab- 

 sent. The largest specimen has a number of impressed revolving lines, stronger towards 

 the base. The description of the operculum is made from the middle-aged, the only 

 one which accompanied the three, and in the older ones this may differ much. In all 

 the specimens before me, the upper whorls are almost entirely covered by the last 

 one. In the full grown one, the deep color of the upper band on the inside continues 

 over on to the callus of the columella. Two other specimens accompanying these are 

 considered by Dr. S. to be the same. They are apparently about half-grown. 

 They differ slightly in form, and totally in the colored bands, which in these speci- 

 mens are replaced over the whole surface with oblong maculations, which, at the 

 upper portion of the whorl run together, and form an irregular longitudinal band be- 

 tween low plications. I have been disposed to think that these two specimens may 

 prove to be varieties of picta, Con., which puts on so many various kinds of bands, 

 but the form is more globose than any picta I have seen. The aperture is nearly the 

 whole length of the shell. Two adult specimens received since the above was 

 written, have coarse transverse striae and one is without any colored bands. The 

 whole surface being a yellowish horn color. The aperture is about 5-6thsthe length of 

 the shell. 



Anculosa Showalterii. PI. 35, fig. 62. 



Testatvalde costata, suborbiculari, crassa, tenebroso-fusca, nigricante, exilissinie striata; spirt brevissinia; 

 suturis valde impressis; anfractibus inflatis, septenis transversis costis indutis; apertura magna, 

 subrotunda, superne subangulata, interne tenebroso-vittata ; columella crassii, planulata, tenebroso- 

 fusca ; labro valde extenso et valde crenulato. 



Shell much ribbed, suborbicular, thick, very dark brown, almost black, very finely 

 striate ; spire very short ; sutures much impressed ; whorls inflated, covered with 

 seven transverse ribs ; aperture large, nearly round, subangular above, with dark 

 bands inside ; columella thick, flattened, dark brown ; outer lip very much expanded 

 and very much crenulate. 



Operculum ovate, thin, with the polar point on the inner inferior edge. 

 Anculosa Slwwalterii, Proc Acad. Nat. Sci.. I860, p. 93. 



