﻿18 



MONOGRAPH OF THE ATLANTIDAE. 



Indian Ocean, 



February 



Utb, 



i 



sp.. 





January 



'06, 



15 



sp.. 



» 



April 



'06, 



12 



sp.. 





March 



'07, 



3 



sp., 



Poeloe Weh, 



March 25, 



'07, 



1 



sp.. 



Java-Sea, 



May 



'06, 



2 



sp.. 



Buitendijk. 



This species is chiefly characterized by the great predo- 

 minance of the last whorl, in comparison to which the 

 spire, with only 2 or 3 whorls, is extremely small; this 

 proportion is more pronounced here than in any other 

 species. Outer lip deeply fissured, keel very high, separating 

 for some distance the inner lip from the penultimate whorl. 

 By Souleyet and Vayssiere transverse ribs, slightly undu- 

 lating, are particularly noticed, especially on the last whorl. 

 I have seen this sculpture only in empty shells of apparently 

 full-grown specimens (3 — 4 mm.), in other cases nothing 

 but faint lines of growth could be detected. According to 

 Souleyet, the fissure in the outer lip, and so also the 

 height of the keel near it, are liable to variations ; specimens, 

 in which this fissure is very deep, were regarded by the 

 latter author as a variety. Among the few type-specimens 

 of Souleyet I have seen, none of them, however, exhibited 

 a high keel and a shallow fissure, near the outer lip. One 

 of these specimens is figured here (figs. 11 and 12). 



Comparing this drawing with those, formerly given by 

 me of A. oligogyra (PL VIII, figs. 14 and 15, 17 and 18), it is 

 evident that they refer exactly to the same species. Little 

 desirous as I am to increase the number of species, I am 

 fairly satisfied to state this fact, adding, that I have alluded 

 in my monograph (p. 55) to the close affinity of the two 

 species. At that time, however, I had no opportunity of 

 studying an authentic A. lesueuri. 



I suppose A. primitia and A. cunicula, both described 

 by Gould, may be the same as A. lesueuri, as I moreover 

 suggested already in my monograph (p. 11) for the first 

 species. Here too the spire is extremely small, and is said 

 to be violaceous, in A. primitia. This colour is also stated 



Notes from the Leyden Museum, Vol. XXX. 



