130 



written A. Grifithsii. As this was merely an error in orthog- 

 raphy, there can be no objection to the use of the name as 

 elsewhere correctly written. 



In the following descriptions of operculated land shells, 

 the opercula are not described, except when important for the 

 diagnosis of the species. We agree with M. Petit, (Journ. de 

 Conch. 1850, p. 39,) who does not find in the opercula of Cy- 

 clostoma characters of sufficient importance to establish gen- 

 era. Certainly they have not sufficient intrinsic value, and 

 it is yet to be shown that they are always expressive of gen- 

 eric differences in the soft parts of these animals. A similar 

 opinion has been expressed by Mr. Redfield, in his catalogue 

 of operculated land shells. Specific differences, however, are 

 often well defined in the opercula. 



Marginella gracilis. Shell between fusiform and cylin- 

 dric, slender : white, with three spiral bands of orange brown, 

 of which the upper one appears on the spire, a part of the 

 middle one is seen in the deflection of the suture in the last 

 part of the penult whorl ; the middle band is sometimes in- 

 distinct : smooth and shining : apex Tather obtuse : spire mod- 

 erately lengthened, with the outlines quite curvilinear : whorls 

 nearly four, moderately convex, with the suture not very dis- 

 tinct ; last whorl long : aperture long and narrow ; lip mod- 

 erately thickened, slightly incurved ; varix slightly extended 

 on the penult whorl ; with four very oblique plaits. 



Length .26 inch ; greatest breadth .09 inch ; least breadth 

 .075 inch ; length of aperture .175 inch. 



This species resembles M. avena VaL, (M. varia Sowb.,) 

 but is much smaller, and much more slender, and has a long- 

 er spire. 



BucciNUM puLCHELLUM. ShcU ovatc fusiform : pale yel- 

 lowish brown, with the spiral ridges dark reddish brown, ex- 



