64 Remarks on Certain Species of 



or fold, where it is reflected, sometimes appressed to the last 

 whorl. The lower angle of the parietal process is connected 

 with the inner termination of the labrnm by a flat, more or less 

 developed callus. The umbilical region is less open, and there 

 is no groove within it on the last whorl. 



This species is variable in size, texture, and sculpture. Mr. 

 Shuttleworth's specimen is opaque, of the color indicated in his 

 description, — irregularly, and, compared with H. auriculata, 

 slightly striated. 



I have one example of large size, from the cabinet of the late 

 Mr. Samuel Lounsbury, which is white, translucent, and almost 

 smootli, — the habitat unknown. 



Of the more common form, usually labelled S. auriculata in 

 American cabinets, I received very many specimens from Mr. 

 Anthony and other correspondents, but without any note of 

 the locality in which they were collected. For one from Corpus 

 Christi, Texas, I am indebted to Mr. W. G. Binney. This 

 variety is of a yellowish horn color, shining, strongly striated 

 above and at the base, and generally smaller than the shel 

 described by Shuttleworth. 



I add the measurements of the specimens referred to : — 



Diam. maj. 11^, min. 10, Alt. 6 mill, whorls 5, Shuttleworth. 

 " " 14: " 12 " Y " " 6, Lounsbury. 



" " 9 " 8 " 5^ " " 5§,W.G. Binney. 



Mc9ix Postelliaaia SSland. 



T. rimato-perforata, snperne convcxiuscnla, costulato-striata, subtus 

 inflato-convexa,]a3viuscula; fnsco-cornea, teniii, iiitida, subpellucida; spira 

 vix elevata; anfr. 5, lente accrescentibus, convexiiisculis, ultimo ad aper- 

 turam deflexo, disjuncto, scrobiculato-constricto ; sntura impressa ; aper- 

 tura alba, obliqua, auriformi, coarctata; perist. acuto, continuo, marginibus 

 plica linguiforini, oblonga, intrante, superne excavata, junctis ; dextro 

 lamella uncata profunde immersa, basali dente lamelliformi, erecto, vix 

 obliquo, intra aperturam producto et recurvato, instructo. 



