COOKE: GEOGRAPHICAL DISTRIBUTION OF MOLLUSCA. 131 



Hneisque increment i obliquis decussantib/is sculpt i ; primi 2-3 

 fusco-purpurei, ultimus paulo pone labrum subconstrictus, ibique 

 epidermide dilute fuscescente amictus ; umbilicus haud pervius, 

 constrictus; apertura magna, livido-carnea, linen pallida externa 

 bipartita; peristoma ad marginem teuue, intus leviler incrassatum, 

 sublate expansum, livido purpureum vel pallidius. 



Operculum paucispirale, comeum, aureum, aufractibus 4-5 

 constitum. Diam. maj. 9 millim., mi//. 6-J-, alt. 9. Apertura cum 

 per is t. 5^ lata. 



This interesting species is about the same size as A. notabilis, 

 Smith, but differs in form, colour, sculpture, and other respects. 

 There are three examples of it in the British Museum, which show 

 but very slight variation in any of its specific features. The indistinct 

 constriction, about 2 h millim. from the peristome, is more or less 

 defined by a dark brown stripe, and, between the stripe and the lip, 

 the whorl is covered with a striated buff or luteous epidermis. The 

 peristome is hardly continuous, but the extremities are connected 

 by a very thin callus. The operculum is quite of the same type as 

 that of A. mefableta, and A. cequivoca, that is, horny, like that of the 

 genus Cyclopliorus, and paucispiral like that of Cyclostou/a, which 

 is shelly. 



I take this opportunity of giving a figure of A. notabilis which 

 was unillustrated at the time when it was described (vide PI. r. 

 figs. 3-4). 



ON THE GEOGRAPHICAL DISTRIBUTION 



OF THE LAND AND FRESHWATER MOLLUSCA OF 



THE MALAGASY REGION. 



By the Rev. A. II. COOKE, M.A., F.Z.S., 

 I'\llow'and Tutor of King's College, Cai/ibridge. 



This interesting and in some respects isolated region includes 

 Madagascar with its attendant satellites Bourbon, Mauritius, and 

 Rodriguez, and the Seychelles and Comoro groups. No land 

 mollusca are known from the Amirantes, the Chagos, or from 

 Aldabra. 



A2 



