8 
SECOND YARKAND MISSION. 
tudinal striation however exists ; all the specimens, young and old, are without exception of 
the peculiar thickness which suggested its excellent name of solidissima ; the five whorls 
agree with those of Kobelt’s original figure, which I suspect was taken from a Lake Pankong 
specimen, and do not show the suhangulation described in the preceding ; the aperture is much 
more expanded than in Kobelt’s typical figure, which was evidently taken from a rather 
young shell, the very thick columella in most specimens agrees with that of the type, but 
in some few it is abruptly twisted back, as in pi. ii, fig. 21 of “ Pcdsch. Moll.” ( L . obliquata, 
v. Mart.) 
These specimens are interesting as removing one of the few slight differences be- 
tween L. obliquata and L. solidissima ; my Pankong specimens clearly show the more expand- 
ed aperture to be merely a question of age and condition, as is also the gradual slope of the 
outer lip ; nearly all my specimens agree in this latter respect with typical obliquata, only 
very few showing the angular outer lip of typical solidissima ; Kobelt in his description 
pointed out the close affinity of the two forms, and also that L. obliquata must be classed 
rather with L. lagotis, than L. auricularia ; the shortened columella seems to me the best 
characteristic of the latter group, as shown in the form I have already described as a variety 
of that species ; the difference is also excellently portrayed in von Marten’s figures, pi. ii, 
figs. 20 and 21, “ Pedsclr. Moll.” The Pankong shell, though always preserving its chief cha- 
racteristics, varies most remarkably, as will be seen from the accompanying measurements. 
The ordinary form : — long. 22, diam. 17^ ; apert. long. 18, diam. 12J mm. 
A form with more produced spire and contracted aperture, agreeing with Kobelt’s figure : 
— long. 22, diam. 15^ ; apert. long. 15 J, diam. 10^ mm. 
A unique form, with quite depressed spire : — long. 19, diam. 15J ; apert. long. VI diam. 
12 mm. 
A form (represented by six or seven specimens), with unusually expanded and more 
rounded aperture : — long. 18, diam. 17 ; apert. long. 111?, diam. 12 mm. 
About a hundred specimens from the shores of the Pankong Lake : both young and old 
specimens show the same peculiar thickness of shell. 
Limn^a lagotis, var. costulata. 
Limnaa lagotis, var. costulata, v. Martens, Fedscli., Keise, Moll., pi. ii, fig. 24. 
More than a hundred specimens were collected by Dr. Stoliczka at Leh, agreeing exactly 
with figs. 22 and 24 {loo. cit.). I cannot consider the forms there figured as belonging to 
even different varieties ; there are numerous individuals amongst the Leh specimens of all 
the forms and of every conceivable connecting link; the variety, as I understand it, appears 
to be fairly constant as regards size and colour ; the spire, too, does not appear to vary much 
more than in the figures quoted; the columella, however, graduates from even a more rounded 
shape than in figure 22 B to the straight (or slightly bent back) form of figure 24 A. 
Long. max. 18J, diam. 12 ; apert. long. 13f, diam. 8f mm. 
Limilea lagotis, var. yarkandensis, nov. 
This is a striking and handsome form, close to the preceding, but half as large again, with 
more produced spire, of five less convex whorls, much stouter texture and straighter, more 
