Hi ^ LAND AND FRESHWATER 



blue-black colour, and had the side of the foot smoothly papillate 

 (above the longitudinal pallial grooves, which are not so well seen 

 as in the ochraceous paler-coloured and smaller specimens). 



One of these measured 30 mm. ; the smallest 17 mm., was 

 olivaceous in colour and unspotted. 



In my original description of the animal I did not allude to one 

 external character, and that is the narrow^ raised ridge on the shell- 

 lobes which runs from the little shell-aperture round the left margin 

 of the shell and towards the respiratory orifice oil the right margin. 

 Similar ridges are seen in Girasia ; they shrink away if the animal 

 is subjected to dry conditions, as in captivity. 



As I said before (Vol. I. p. 242), the genitalia (Plate XCIII. 

 fig. 1 a) are very similar to Girasia, but the amatorial organ is much 

 smaller both in length and diameter as compared with the organs as 

 a whole or with that of Girasia. The spermatheca in the example 

 dissected and figured is very large, showing the expansible nature of 

 the envelo])ing membrane. There is also an expanded bag-like 

 portion of the uterus (oi'<) just below the point where the vas deferens 

 is given off; this is not seen in Girasia. In this specimen the sperma- 

 theca contained no less than twenty-two spermatophores whole, and 

 the broken parts of three or four others — a far greater number than 

 I have ever counted in any species before. They are of the usual 

 form (figs. 1 h, 1 c), and like that of Girasia, the edges of the gutter 

 (from a to h) being spineless. Short strong spines occur at the base 

 of the capsule, and long delicate ones at the anterior end of the 

 gutter-like portion or flume. Mr. Webb has not understood the true 

 form of this apparatus, and has united together detached portions of 

 several spermatophores in the figure, no. 0, pi. ix. 



The shell differs from that of M. beddomei, which is figured on 

 Plate LXII., in being thin, membranaceous, and transparent on the 

 margin, while the latter is solid and shelly. Pig. 1, Plate XCIII., 

 is the sliell of the large black specimen, and is quadrate in form. 

 Figs. 2 h, 2 c is that of the more olivaceous-green specimen, in 

 which the apex is larger and the shell narrower and longer. These 

 shells are similar (thin in texture) to the typical shell in the 

 British Museum, 21. chissuinieri. 



The radula (black specimen) had the formula — 



88 . 3 . 20 . 1 . 20 . 3* . 88 

 111 . 1 . Ill 



a less nvtmber than in M. heddoinei. 

 Another specimen : — 



95 . 2 . 18 . 1 . 18 . 2* . 95 

 115 . 1 . 115 



* There is often a doubt in counting these intermediate teeth, whether to 

 include one or more of them in the median or liiterals, they change so very 

 gradually in their form. The proportion in breadth of tlie median band of 

 teeth, on large plates, to the breadth of the narrow -plated, feeble laterals, is 

 the important point, and in the above ibrmuhv woidd perhaps be better shown 

 thus : 88 . 47 . 88 ; 95 . 41 . 95, respectively. 



