20 LAND AND FRESnAVATER 



December, 1830. I also procured dead shells from the rocks of 

 Patharghata. It appears to be very plentiful in all these situa- 

 tions. I never met with it to the westward, either in the plains 

 or among the rocks or hills of the Yindhyan ranges which border 

 those pLiins to the soutliward. I have seen a worn specimen in a 

 collection of shells made twenty-two or twenty-three years ago in 

 Ceylon [this must be some other species]. The young shell being 

 destitute of the thickened and continuous peristome, as well as of 

 the rich orange colour Avhich adorns that part, might, if met with 

 destitute of an inhabitant, be easily mistaken for a Helix. The 

 ])eristorae when first reflected is also free from the orange colour, 

 which it does not acquire until thickened and fully grown. 



" In its exterior anatomy the animal differs from that of Cijclo- 

 sfoma eleffmis, as described by the Rev. M. J. Berkeley, A.M., in the 

 ' Zoological Journal ' (vol. iv. 1828-29, p. 278), only in the following 

 particulars : — The foot has an oblong-ovate disk somewhat pointed 

 behind, instead of an oval one pointed before and behind. The 

 summits of the tentacula are not inflated, and are translucent 

 instead of being opaque. The edge of the mantle is even, not 

 crenulated. Lastly, the operculum is horny, not testaceous, and 

 consists of many volutions instead of three, differing in the manner 

 of construction from that of Cyc. elajans as much as that of Lit- 

 torina does from the operculum of Trochus. Like the cognate 

 genus Helidna, the animal uses its tentacula alternately to examine 

 its path by means of the sense of touch. 



" The colour of the animal is livid with some dark olive shades. 

 The tentacula are blackish-olive with the exception of the trans- 

 lucent summits." 



Amended cliaracters of the Genus. 



Aiiimal. Edge of the mantle free all round : sole of foot un- 

 divided ; eyes at lower base of annulated tentacula. The male 

 organ close below the right eye. 



Teeth of radula •> ' a ' 3 " 3 * 3 * 3 ' 2 ' "^^^ centre the largest, 

 tricuspid ; the side teeth narrow and elongate, tricuspid or 

 bicuspid. 



Operculum orbicular, horny, thin, more or less concave exter- 

 nally, with numerous narrovr whorls and a large or small central 

 nucleus. 



Shell globosely turbinated, depressed or discoidal, usually widely 

 umbilicated ; aperture circular ; peristome continuous, straight or 

 ex])anded. 



The description of the animal from life, taken from one of Ci/clo- 

 pliorux zebrinns (Conch. lud. pi. ii. fig. 2), of the Khasi Hills, is as 

 follows : — " With long slender-pointed tentacles ; eyes at base, as 

 usual in this family. The mode of progression is very unlike that 

 of the Helicida;, with their eye-tentacles. It was curious to watch 

 the careful manner and the frequency with which the tentacle used 

 as a feeler was brought in contact with every projection in advance 



