84 Bulletin ii 84 



Whitfield's original description. — "Shell minute, broadly ex- 

 panded; spire very low; volutions from twoto'three. the outer one 

 forming the greater part of the shell; peristome continuing 

 around the body of the volution to near the base of the columella; 

 margin of the aperture flattened or slightly reflecfted; inner sur- 

 face of the shell highly polished; exterior marked by irregular 

 lines of growth. The different individuals differ somewhat in 

 degree of expansion of the outer volution. 



''Dimejisiofis.— Tho. largest individual seen measures .05 inch 

 across the aperture. 



^'Locality. — Six miles below Prairie Bluff, Ala., in sand, filling 

 the cavities of other shells." 



Regarding this species ^''Velutina expansa'^ Aldrich says, loc. 

 cit.: "Prof. Whitfield informs me this species was obtained 

 from the dirt out of a large Valuta newcombiana Whitf. As the 

 only locality of this species is at Bell's landing, the habitat of 

 this form is fixed. The species has a very suspicious resemblance 

 to a very young or embryonic Infundibuhi7n trochifornie L/am." 



The largest embryonic whorl is spirally lirate, and the smallest 

 whorls are sunken or hidden by the largest, features not at all in 

 harmony with Whitfield's " V. expansa,'' whereas the young of 

 C. compiedus Aid. are exadlly V. expansa Whitfield. We have 

 it in all stages of growth. The smallest whorls of the embryo 

 are not sunken as in Calyptrcea trochiformis , but appear like the 

 smaller spirals of a very small Natica. 



Localities. — Ala.: Woods bluff; Gregg's landing; Bell's land- 

 ing; Nanafalia; 3 mi. s. w. of Thomasville. Hatchetigbee and 

 Libson. — Aldrich. 



Type. — Hall's colledtion. 



Specitnen figured. — From Woods bluff; Paleont. Mus., Cornell 

 Univ. 



Calyptraea aperta, PI. n, fig's. 13-16. 



Syn. Trochus apertus Sol., Foss. Hant., 1766, p. 9, fig's, i, 2. 

 T. opercularis Sol., idem, fig. 3. 

 Calyptrcza trochiformis lyam., Ann. du Mus., vol. i, p. 385, 1802; 



vol. 7, pi. 15, fig's. 3 a, b, c, d, 1806. 

 Trochtcs calyptrceformis Lam., An. sans. Vert., vol, 7, p. 55S, 

 1822. 



