1$ DR. NELSON ANNANDALE ON 



globose than" in the forma typica, but in others it is not so, while in 

 one shell it is actually depressed as a whole and its suture is deeply 

 and broadly canalized. 



The surface of the shell is dull and the sculpture is coarser 

 and at the same time more regular than that of the typical P. turb- 

 inis, though similar in general character. 



The colour is olivaceous brown externally with fairly regular 

 curved longitudinal dark lines. The interior of the shell is uniform 

 white in the specimens I have examined, but these are all "dead". 



The operculum is thick and heavy in these specimens and 

 incrassated somewhat at the two extremities. The scar is large and 

 its smooth area extensive ; the sculptured border of fairly uniform 

 width, rather shallow and irregularly and by no means deeply 

 sculptured. 



Measurements (in millimetres) and Proportions of Shells. 

 Height 



Maximum diameter 

 Height of mouth 

 Maximum diameter of mouth. . . 

 Maximum diameter to height... 

 Maximum diameter to height 



of mouth 

 Height of mouth to height . . . 

 Maximum diameter of mouth 



to maximum diameter ... 1:2. 13 1:2 1:2. 25 



This race was described from Northern Siam. The series I 

 have examined is from Pitsanuloke. 



Kace subampullacea Nevill. 

 1884. Ampullaria turbinis var. subampullacea, Nevill, opcit., supra, 



p. 6. 

 1891. Ampullaria turbinis var. subampullacea, Mollendorf, Proc. 



Zoo. Soc. London, p. 346. 

 This race has the shell higher and less transverse, with the 

 mouth higher narrower and more oblique, and the spire more promi- 

 nent and pointed than the typical form. There are Si. whorls. The 

 shell is not so thick and globose as in the race dalyi but rather 



JOURN. NAT. HIST. S'OC. SIAM. 



