MOLLUSC A. 
11 
others brought hack by Dr. Stoliczka ; it differs mainly in two respects, colour and shape 
of the aperture, in the latter respect agreeing with pi. iv, figs. 10 — 12, “ Mai. Bl. ” xxii, 
Ice vis, Aid.) — shell resembling the above figures, hut of a rich chestnut brown, and with 
the umbilicus a little more open ; the aperture is considerably more laterally expanded 
than in the forms I have grouped under P. albus, and consequently relatively not so 
high. 
Diam. 6, alt. 1^ mm. 
About a hundred specimens from Leh. 
22. Planorbis (Tropidiscus) subangulatus, Phil., var. 
Planorbis subangnlata, Phil., “ Moll. Sicil. ” 1814, pi. xxi, fig. 6 (Sicily). 
Pour specimens only were found at North Tangitar; the form is a very remarkable one, 
and may, I think, prove to he new ; it is very different from Persian specimens of P. suborn - 
gulatus , as also from European P. marginatus ; the angulation is less distinct than in the 
former, the whole shell more compressed and flattened out, the spire showing distinctly 
all five whorls ; the aperture is more contracted, and the under side less deeply sunk. 
PI. iii, figs. 23-24, “ Malakozoologische Blatter,” 1875, gives an almost exact representation 
of the form ; the shape of the aperture is quite different from that of fig. 22, being higher 
than the body whorl and not bent down ; of course these figures are magnified views of a 
minute and quite different species ; a fair idea of the shell may, however, be obtained from 
them. 
Diam. 8, alt. If mm. 
Persian specimens of P. subangidatus measure — diam. 7-|, alt. 2 mm. 
23. Planorbis (Segmentina) nitidus, Mull. 
Planorbis nitidus, Muller, Hist. Vermium. p. 163. 
Twelve specimens of a small form from Yarkand. 
24. Planorbis (Hippeutis) complanatus, Lin. 
Planorbis fontanus, Lightf. (England) . 
Ten specimens were found with the preceding at Yarkand; they are also a small variety. 
25. Planorbis (Armiger) natjtileus, Lin. 
{Fide Westerl. , Mai. Bl., 1875, p. 115 = P. crista, Lin., var.) 
I detected seven specimens of this interesting minute form inside the apertures of the 
Yarkand specimens of Limncea; the margins of the aperture are continuous; I can detect 
no signs of transverse ribs, and the form is most certainly specifically distinct from my 
English specimens of L. crista, L., as represented in “ Malakozoologische Blatter,” pi. iv, 
fi-s! 25—27 ; the Yarkand shells agree very fairly with figs. 28-30, loc. cit. 
Diam. 2f mm. 
