1919. | N. ANNANDALE & B. PrasuHaD: Mollusca. 41 
Key to the Shells of Limnaea known from Baluchistan 
and Seistan. 
1. Shell thin, moderately small ; its mouth large and 
more than half as long as the shell. 
A. Mouth expanded and_ projecting posteriorly 
from shell at a right angle; its outer arc prac- 
tically a semi-circle... oe % 
B. Mouth not or little expanded, usually projecting 
at an angle much less than a right angle ; 
its outer arc less than a semi-circle. 
i. Spire exserted, with swollen whorls and im- 
pressed suture ; main axis of mouth forming 
an acute angle with that of shell ... L. bactriana. 
ii, Spire much less exserted ; its whorls not swol- 
len and its suture not impressed ; main axis 
of mouth parallel to that of shell. 
4. Outer arc of mouth quite regular; apex 
L. persica. 
sharply pointed... co ~. LZ. tvanica. 
b. Outer arc of mouth irregular; apex bluntly 
pointed. 
1. Curve of outer are of mouth only slightly 
flattened at wae ... L. gedrosiana, SS. 
>, Curve of outer arc of mouth flattened 
toa straight line ee ... LL. gedrosiana 
var. vectilabrum. 
>. Shell moderately or very thick, of very small size, 
elongate, with the length of the mouth much less 
than half the total length. 
1. Apex pointed ; whorls of spire moderate .., L. tyuncatula. 
2. Apex blunt; whorls of spire very large... L. hordeum. 
Limnaea persica, Issel. 
(PI. v, figs. 3-6.) 
Limnaea auricularia vat. persica, Bourguignat, Issel, Moll. Miss. 
Ital. Persia (Torino), p. 47. 
1883. Limnaea persica, Locard, Arch. Mus. Hist. Nat. Lyon I\I, p. 285. 
1865. 
on 
Issel gave a very brief description of this form, which he did 
not figure, merely comparing it with L. auricularia and stating 
the length and breadth of the shell. Locard had probably seen 
specimens, as he compared his L. subpersica with it, but gave no 
further details. It seems to us impossible that the form which 
Nevill! called Limnaeus lagotis var. persica, Issel (= L. trvanica, 
nobis) can be identical, as that form has no particular resemblance 
to L. auricularia. 
We have before us a series of shells? collected by the late Dr. 
W. T. Blanford at Saidabad, S.W. of Kerman (the type locality). 
The measurements of one of these agree almost precisely with those 
given by Issel. We have also a much larger series from the Balu- 
chistan desert clearly belonging to the same species but differing 
slightly. Fully adult shells from the former locality are somewhat 
broader than Issel’s type, the specimen that agrees with it being 
not quite full-grown, and we do not know from what kind of 
l Nevill, Hand List Moll. Ind. Mus. \, p. 237 (1879). 
2 Identified by Nevill as L. auricularia, var. (op. cit., p. 238). 
