﻿20 



MONOGRAPH OF THE ATLANTIDAE. 



Indian Ocean, August '06, 1 sp., Buitendijk. 



„ November '06, 1 sp., „ 



Gulf of Aden, December '05, 1 sp., „ 



Gulf of Bengal, August '06, 1 sp., „ 



I have nothing to add to my former description 

 (monograph, pp. 56 and 57, PL VIII, figs. 19—21). Spire 

 consisting of 5—7 whorls, the first 3—5 slowly and 

 regularly increasing, penultimate and especially last whorl 

 rapidly enlarging. In order to show the peculiar sculpture 

 of this species and some other characters, I have figured 

 two shells (figs. 13 — 16). In fig. 13 some (5 — 6) distinct 

 spiral lines are visible on the first half of the penultimate 

 whorl; I believe this sculpture to be dependent on age, 

 however, as it is gradually disappearing in larger shells 

 of somewhat more than 2 mm. Fissure in outer lip very 

 wide, but shallow. Two whorls visible at under side of the 

 shell. Colour absent on the last whorl, spire faintly brownish, 

 and this colour is particularly pronounced on the suture. 

 The same tint occurs sometimes at the inner lip. Aperture 

 very large. 



A. quoyana of Souleyet was not represented in the 

 material from the Paris Museum. I venture to suggest 

 that it may be the same as A, inflata. In the material 

 procured by Mr. Buitendijk I found some specimens (figs. 

 15 and 16), which agree rather well with Souleyet's figures of 

 A. quoyana (copied in my monograph, PI. I, figs. 38 and 39), 

 though these are much too small. Seen from above, the 

 shells of the typical A. inflata with its characteristic spire 

 (fig. 13) and that of » A, quoyana"" (fig. 15) of Mr. Buitendijk 

 agree entirely (except as regards the sculpture, which is 

 absent in the latter), and so do the side-views (figs. 14 and 

 16); the operculum is also wholly the same (»>4. quoyana'\ 

 fig. 17) and shows a double spiral line, but no trace of 

 parallel lines ^). 



1) Tt may be possible that this negative character is dependent on age, 

 and that the lines make their appearance in quite full-grown shells. 



Notes from the Leyden Museum, Vol. XXX. 



