Ig19.] N. ANNANDALE & B. PRAsHAD: Gastropod Molluscs. 107 
on the molluscs of Seistan may be consulted (see plates vi, vii, 
Xiii, xiv of this volume). 
Limnaea gedrosiana, Annand. and Prashad. 
1918. Limnaea subpersica, Annandale, Rec. Ind. Mus. XV, p. 146, 
Plex Ho he 
1919. Limmaea gedrostana, Annandale and Prashad, Rec. nd. Mus. 
XVIII, p. 48, pl. vil, figs. 2-4. 
There is in Captain Boulenger’s collection a fairly good series 
of specimens in spirit which we cannot separate from our recently 
described species. The shells, however, though not thicker or 
less fragile, possess much stronger longitudinal ridges on the body- 
whorl than specimens from Seistan or Baluchistan. ‘There is no 
spiral sculpture. The mouth of the shell is also as a rule a little 
narrower, but this difference is hardly beyond the limits of normal 
variation and is not so great as that observed between shells from 
Baluchistan and those from Seistan. The largest shell is 10 mm. 
high and its maximum diameter is 7 mm. The specimen recently 
figured by one of us provisionally as L. subpersica, Locard, is a 
very young shell of this species. 
The radula is so variable in L. gedrosiana that it cannot be 
regarded in this species as possessing sound diagnostic characters. 
In a specimen from Mesopctamia it is very like that of some 
individuals from Baluchistan. 
The genitalia resemble those of the Seistan form figured and 
described by us in the original description of the species. Some 
differences exist, but these are due to the fact that the Seistan 
specimen we figured was abnormal in certain respects, as is borne 
out by dissection of another specimen from the same country. This 
specimen was found to have the genitalia quite similar to those of 
specimens in the present collection. The abnormality in the indivi- 
dual figured consisted in the large development of the accessory 
gland and in the poorer development of the hermaphrodite gland, 
its duct and the uterine duct; all these latter structures are much 
better developed in normal specimens, while the accessory gland is 
usually a small structure. The proximal part of the vas deferens 
also is rather thicker in normal specimens. 
It is clear, therefore, that individual differences must be looked 
for in the genitalia as well as in the shell and radula of species 
belonging to this group of Limnaea. 
The precise locality of Capt. Boulenger’s specimens is given 
by him as ‘‘ higher reaches of Khandag Creek, Basra, Mesopota- 
mia.’’ The species is not uncommon in swamp-deposits in the 
delta of the Euphrates. 
Limnaea bactriana, Hutton. 
(Ph SIV, fig. 33) 
1919. Limnaea bactriana, Annandale and Prashad, Rec. Ind. Mus. 
XVIII, p. 45, pl: v,-figs. 1, 2% pl. vil, fig. 6. 
