MOLLUSCA. 11 



others brought back 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, 

 (P. Icevis, Aid.) shell resembling the above figures, but 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 (Tuoproiscus) SITBANGULATUS, Phil., var. 



Planorbis subangulala, Phil., " Moll. Sicil. " 1844, pi. xxi, fig. 6 (Sicily). 



Four specimens only were found at North Tangitar ; the form is a very remarkable one, 

 and may, I think, prove to be new ; it is very different from Persian specimens of P. suban- 

 gulatus, as also from European P. nmrginatus ; 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. 



PL 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. subangulatus measure diam. 7^, alt. 2 mm. 



23. PLANORBIS (SEGMENTINA) NITIDUS, Mull. 



Planorlis nitidus, Miiller, Hist. Vermium. p. 163. 

 Twelve specimens of a small form from Yarkand. 



24. PLANORBIS (HIPPEUTIS) COMPLANATTJS, Lin. 



Planorbis fontanus, Lightf. (England). 

 Ten specimens were found with the preceding at Yarkand ; they are also a small variety. 



25. PLANORBIS (ARMIGER) NAUTILETJS, 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 I/imncea ; 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, 

 figs. 25 27 ; the Yarkand shells agree very fairly with figs. 28-30, loc. cit. 



Diam. 2|- mm. 



