26 STROBILOPS, C.ySTADA AND UNITED STATES, 



2a. Stroiilops texasiana floridana (Pils.). PL 2, figs. 1-4. 



The shell is conic with convex outlines, almost dome-shaped ; 

 the periphery only weakly angular, the base convex; rather 

 solid; brown, the summit whitish-corneous. Umbilicus con- 

 tained about 8 times in the diameter. Whorls 5i/^, the first 

 two smooth, the rest sculptured with narrow, rather widely 

 separated ribs (about 30 on the last whorl). These ribs con- 

 tinue on the base, which is radially ribbed. Aperture semi- 

 lunar, the peristome thick, narrowly reflected, brown or 

 whitish; parietal callus rather thick at the edge. Parietal 

 lamella emerging to the edge of the callus, penetrating inward 

 fully a whorl (PI. 2, fig. 3). Infraparietal lamella scarcely 

 emerging, penetrating as far inward as the parietal lamella. 

 The inner half of this lamella and of the parietal is nodose, 

 the nodes minutely asperate. Interparietal lamella very low, 

 about a half-whorl long, nodose, penetrating as deeply as the 

 parietal lamella. There is one small, short axial lamella and 

 four basal folds, the outer one peripheral in position ; a single 

 palatal fold is generally developed. These folds form a 

 curved, very obliquely radial series, the middle of which is 

 about a half-whorl back of the aperture. The two inner basal 

 folds are much stouter and higher than the others, the second 

 from the axis (or third, counting the axial) being the longest 

 and highest of the folds, and somewhat sinuous (PL 2, fig, 4) . 



Height 2, diam. 2.4 mm, (Miami), 



Height 1.9, diam. 2.2 mm. (Orlando). 



Florida: Miami, Dade Co., type locality (S. N. Rhoads, M. 

 Hebard, Pilsbry). Throughout the State, from Sugarloaf, 

 Boca Chica and No-name keys to Clay Co. on the St. Johus 

 River and Jackson Co. on the Chipola. 



StrohUops floridanus Pilsbry, Nautilus XXIII, Dec. 1909, 

 p. 90. — Vanatta, Naut. XXVI, pp. 21, 33 (No-name Key, 

 Sugarloaf Key) .— Wenz, Naehrbl. D. M. Ges. 1916, p. 184.— 

 Walker, Naut. XXXI, p. 56 (Palm Beach). — ;S^. labyrinthica 

 Rhoads, Naut. XIII, p. 45. — Johnson, Naut. XIII, p. 142, 



This form differs from ;S^. labyrinthica by its widely-spaced 

 ribs and long parietal lamella. This is typically a full whorl 

 long, or somewhat more, thus differing from S. texasiana in 



