1921.] B. Prashad : Sumatran Molluscs. 481 



form, but in the large series the following five varieties can be 

 distinguished : — saleycrica, scalaris, lacvior, borneensis and moussoni. 



var. laevior (v. Martens). 



iSy;. Vivipara costata \ar. laevior, v. iMartens, op. cit., p. 21, pi. li, 



figs. 5. <5-. 

 igog. Vivipara javanica laevior, Kobclt, op. cit., p. 253, pi. xlviii, 

 figs. 3-6. 



The form as the Sarasins ' and Kobelt have shown is a variety 

 of V. javanica and not of V. costata as von Martens considered it 

 to be. I have one of von Marten's co-types before me and agree 

 with the opinion of these authors. 



Most of the Sumatran specimens agree closely with von Mar- 

 tens' co-tj'pe and his figures, except that they are a little broader 

 and less elongate. The operculum agrees with Kobelt's fig. 3 

 {loc. cit.). The specimens are mostly olive brown in colour, but 

 some of them are much darker owing to a deposit on the surface. 

 The largest specimen is smaller than the largest of von Martens' ; 

 it measures 28'2 mm. in length by 20 mm. in breadth, and the 

 aperture is i4-8 mm. by 11 '6 mm. 



The specimens before me are from fresh-water areas at Medan 

 and Mariendal (Deli) ; also from the Soengei Krah (Medan) ; and 

 the Soengei Minahol. 



This variety was hitherto known from Java and South 

 Celebes only. 



var. saleyerica, v. Martens. 



1897. Vivipara javanica var. Saleyerica. v. Martens, op. cit., p. 24. pi. 



"' ^S- 3- 

 1909. Vivipara javanica saleyerica. Kobt-It, op. cit., p. 235, pi. xlviii. 



fig. 16. 



The only adult specimen of this variety in the collection is 

 from the Soengei Minahol. It agrees closely with one'of v. Mar- 

 tens' co-types before me. The specimen is of a yellowish brown 

 colour with dark transverse bands on the first three whorls, and 

 measures 17-4 mm. by i2'5 mm., the aperture is 10-5 mm. by 

 8-3 mm. 



I also assign to this form, with some doubt, two young shells 

 from a fresh-water area at Padang Boelan (Deli). These specimens 

 are not larger than 12 mm. in length, have a fairly prominent 

 keel on the body-whorl and are narrowh' umbilicate. They are 

 of an amber-brown colour. 



This record greatly extends the range of this form, which 

 was only known from vSaleyer. 



var. moussoni, v. Martens. 



184.9. Paludina aiigiilaris (iiec .Miill.), Mousson, Moll. 'Java, p. 62, 

 P • viii, fig-. 5. 



I Moll. Celebes, p. 64 (Wiesbaden, 1898). 



