MOLLUSCA. 7 



Long. 23, diam. 19f ; apert. long., 18^ diam. 14 mm. columclla, at junction with body 

 whorl, 2 to 2| mm. in breadth. 



About 20 specimens (dead) on the shore of Lake Sirikul or Victoria, Pamir. 



Another variety is smaller and more deh'cate than the above, but with the same remark- 

 ably thickened and rounded columella, as is well represented on pi. ii, fig. 20, " Fedsch. 

 Moll."; the spire, however, in the Aktash specimens is more prominent and the broadly 

 reflected columella even more marked. 



Long. 16f , diam. 13 ; apert. long. 13, diam. 10 mm. 



A deformed specimen measures long. 12J, diam. 12 mm. 



About 30 specimens were taken alive in a stream at Aktash (Sarikol). 



15. LIMN^A DEFILIPPII, Iss., var. SIBIKULENSIS, nov. 

 Issel, Moll. Persia, 1865, pi. iii, figs. 26 & 63 (Lake Gokcha, 5,500 feet). 



This is perhaps the most remarkable of the Yarkand species of Limncea and the furthest 

 removed from the typical forms of L. auricularia and L. lagotis, even more so than typical 

 L. defilippii. As justly pointed out by Issel, it is intermediate between the above group and 

 that of L. stagnates. It differs from Issel's figure by the much more swollen, subangulate 

 whorls, and by the shorter, not twisted and evenly rounded columella ; the produced spire and 

 malleated texture are very characteristic of both. 



I had already written the following description before I read that of Issel. 



Shell in size intermediate between L. stagnalis and L, lagotis ; of moderately thin tex- 

 ture, the same as in L. stagnalis ; spire much more produced than in L. lagotis ; whorls six, 

 remarkably subangulate ; aperture expanded as in fig. 10, pi. ii, " Mai. Bl.," 1870 ; colu- 

 mella broadly reflected, almost completely covering the umbilicus, not twisted in the least, 

 evenly rounded at base as in fig. 9 (loc. cit.) ; very young specimens present a remarkably 

 close resemblance to those of L. stagnalis, the subangulation of the whorls and short, 

 straight columella being naturally less distinctive than in full-grown specimens ; the surface 

 of most specimens is more or less roughly decussately malleated ; under the lens a very fine 

 and close longitudinal striation can be seen. 



Type of var. sirikulensis : long. 30J, diam. 21 ; apert. long. 20, diam. 14| mm. ; the 

 ante-penultimate whorl measured from the outer lip 6f mm. ; a young specimen measured 

 long. 24|, diam. 14 ; apert. lat. 14, alt. 9J. 



Fourteen dead specimens found, on the shores of Lake Sirikul, in company with L. auri- 

 cularia, var. 



16. LIMN.EA LAGOTIS, Schr. 



Limncea Iag6tis, Schr., Fauna Boica, iii, 1803. 



L. lagotis, var. solidissima, Kobelt, Malakozoologisclie Blatter, 1872, pi. ii, figs. 17 & 18. 



L. oUiquata, v. Mart., Mai. Bl., 1864, pi. iii, figs. 9 & 10 (Lake Issik-kul). 



A fine series of this remarkable variety was procured by Dr. Stoliczka in all stages 

 of growth ; it varies greatly in the more or less produced spire, though never, even in 

 its most elongated form, approaching the preceding form ; there is little, if any, trace of 

 the malleated sculpture, often so characteristic of the preceding : the same fine longi- 



