90 THE NAUTILUS. 



Helicina orbiculata clappi, n. subsp. 



The shell is less globose than orbiculata, tending to a more trochi- 

 form shape, the last whorl being very obtusely subangular at the 

 periphery. The outer lip is more broadly expanded, thin, and there 

 is only a weak angle or none at the junction of columella and basal 

 lip. The color is white, very pale citrine, white with two red bands, 

 or uniform red, the lip and apex pale. 



Alt. 8, diam. 9 mm. 



Alt. 7, diam. 8 mm. 



Alt. 6.1, diam. 7.3 mm. 



Distribution: Southern Florida, Dade, Lee and Monroe counties; 

 types from Miami, Dade Co., collected by S. N. Rhoads and H. A. 

 Pilsbry, 1899. On the east coast H. o. clappi extends as far north 

 as Palm Beach (Pilsbry, 1899); on the west coast to Evans' Planta- 

 tion on the Manatee River (C. T. Simpson). 



Key to Subspecies of H. orbiculata. 

 a. Last whorl globose, periphery well rounded; a distinct tooth or 

 angle at base of the columella. 



b. Lip thin or not much thickened, H. orbiculata. 

 bb. Lip much thickened, II. o. tropica. 

 an. Last whorl very obtusely subangular, the shape approaching 

 trochiform; no distinct tooth at base of the columella, H. o. 

 clappi. 



Strobilops floridanus, n. sp. 



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. Whorls 5^, the first two smooth, the rest 

 sculptured with narrow, rather widely separated ribs (about 30 on 

 the last whorl). These ribs continue on the base, which is radially 

 ribbed. Aperture semilunar, the peristome thick, narrowly reflexed, 

 brown or whitish; parietal callus rather thick at the edge. Parietal 

 lamella emerging to the edge of the callus, fully a whorl long. 

 Infraparietal lamella scarcely emerging, penetrating as far inward as 

 the parietal lamella. The inner half of this lamella and 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 axial lamella and four basal plicae, 



