124 Chusan Shells. [No. 2. 



West Indies, which Sowerby arranges as an Achatina. In all these 

 shells there is a slight evasion or sinuation of the base of the mouth, 

 occasioned by the protrusion of the outer lip ; but in none of them 

 is there the decided truncation of the base of the columella which 

 distinguishes the true Achatina. Dr. Cantor's shell approaches most 

 nearly to those forms of Achatina which are represented by A. oc- 

 tona (subgenus Macrospira, Swainson,) but it cannot, notwithstand- 

 ing its elongated form and oblong aperture, be received into Swain- 

 son's subgenus Leptospira, by which he makes the transition to 

 Achatina from Bulimus, with reference to the character assigned by 

 him to the outer lip of Leptospira ; and it agrees still less with his 

 figure of L. signata, which possesses an exserted aperture with a 

 free border. It is nevertheless not distantly related to Bulimus decol- 

 latus, which he would place in that sub-genus. In one adult speci- 

 men sent, the inner lip and base are considerably thickened by a de- 

 position of shelly matter, added like an anterior lip after the animal 

 had attained its full growth. In its habit of carrying its shell erect, 

 the animal differs from our Indian species, which although it occa- 

 sionally lifts its shell a little, ordinarily trails it behind. 



" Invariably found in company with Clausilia aculus. Except in co- 

 lour, the animals are alike. In habits they differ only in one respect. 

 The Clausilia drags the shell along with the apex touching the 

 ground, while the other carries the shell erect on its back. A. erecta 

 was also found by Dr. Cantor at Macao, although not accompanied by 

 the Clausilia, which he only met with at Chusan. 



Plakoebis papykacetts, Benson. 



Testa compressa, olivaceo-cornea, sub-polita, minutissime radiato- 

 striata, anfractu ultimo latiori, supra infraque sequaliter convexo ; 

 peripheria carinata, spira basique ambabus depressis, umbilicatis ; 

 umbilico inferiori arctiori ; labro superiori valde prominente, semi- 

 circulari ; inferiori recedente, recto. 



Diam, 0.4 poll. 



" Eound in canals and ponds attached to Char a ; not numerous. It 

 is to be observed that the canals at Chusan communicate with the sea 

 (those of Ting-hae, of course more immediately so,) and although the 

 water is fresh and inhabited by frogs, fresh-water fishes, Lytiscus, 



