1919.] N. ANNANDALE & B. PRASHAD: Gastropod Molluscs. 113 
The type-series consists of recent shells and was collected by 
Capt. C. L. Boulenger in a marsh five miles north of Samara on 
the lower Euphrates. Col. W. H. Lane also obtained many broken 
subfossil shells in a lake-deposit at Nasariyeh. 
Limnaea cor bears a tesemblance, perhaps quite superficial, to 
certain forms of L. auricularia and allied species or races, but the 
direction of the spiral, the form of the spire and body-whorl and 
especially the comparatively narrow, quadrate or subquadrate out- 
line of the mouth are very different on actual comparison. It is 
probably an extreme form derived from L. lagotis. The young 
shell departs much less conspicuously from this type than the 
adult. It is unfortunate that we have no anatomical material. 
Limnaea tenera race euphratica, Mousson. 
(Pl. XIII, figs. 3-5.) 
1874. Limnaea euphratica, Mousson, Fourn. de Conchyl. XX1, p. 4o. 
1918. Bere tenera, Annandale, Rec. nd. Mus. XVI, p. 165, pl. xx, 
§: 3: 
At first sight the shell looks like a connecting link between 
L. peregra canalifera and L, cor, but many differences from both 
appear on a close inspection. Both the adult and the young shell 
are more like those of L. cor. 
The differences from L. cor to be noted in the dorsal aspect 
of the mature shell are the following. The spire is longer and more 
prominent and has its basal whorl less depressed and more swollen 
and its suture less transverse. The upper surface of the body- 
whorl is less broadly flattened and the suture above it less trans- 
verse. The outline of the shell is more graceful and still more 
asymmetrical. The upper part of the inner margin is less convex 
and the slope inwards more abrupt and the terminal lobe more 
prominent and narrower. ‘The outer margin is practically semi- 
circular. The sculpture of the surface is less regular and the com- 
posite longitudinal ribs less distinct and less curved. 
In ventral view the part of the body-whorl visible is longer, 
narrower and less tumid. Its upper margin is more oblique and 
less flattened. ‘The spire is considerably shorter than in the dorsal 
view. The upper extremity of the mouth is removed from that of 
the body-whorl by a distance nearly equal to the length of the spire 
as seen in this view. ‘The outline of the mouth is regularly oval. 
The lip at its inner anterior extremity is distinctly expanded and 
flattened. The callus is poorly developed above the columella, 
which is straighter. 
As seen from above, the most noteworthy differences between 
the shells are, apart from those already noted in the dorsal and 
ventral views, (I) that the surface of the body-whorl is much less 
concave and that its concavity near the lip has a less confined 
character; (2) that the lip on leaving the shell has at first a com- 
paratively narrow concavity and then proceeds outwards and back- 
wards abruptly with a slight arc. 
