150 LAND ANB FKHSnWATER 



absent. The retractor muscle of the male organ (fig. 4 a) is given 

 off from the head of a large ovate swollen mass, which corresponds 

 with the coiled mass seen in Oxytes orobia. There is a short flagellum 

 or kale-sac. The spermatheca is moderately long and consists of 

 an ovate membranous portion situated on a lower thick muscular 

 tube (fig. 4 h) ; the albumen-gland was small ; the hermaphrodite 

 duct extremely convoluted. 



Jaw (fig. 5) with a large central projection. 



The radula (fig. 6) has this formula : — 



40 . 2 . 17 . 1 . 17 . 2 . 40 

 59 . 1 . 59 



The central tooth is tricuspid, the admedians also tricuspid, the 

 inner well developed and standing higher than the outer, which is 

 the largest. The marginals are curved, bicuspid, the outer cusp 

 below the inner. 



Of this species there were only two specimens in the collection 

 with similar sculpture on the shell — one an adult, from which 

 the above description has been made, and the other a much younger 

 example Avhich I have left in the shell ; the pallial margin and 

 markings on the visceral sac are the same in both. 



The anatomy of this animal is so very unlike any I am acquainted 

 with, that I found it impossible to put it into any previously described 

 genus of Indian land-shells, and I have therefore created a new 

 subgenus for its reception. 



I must call attention to a very interesting point connected with 

 this species : it is so remarkably like another in its shell-character 

 inhabiting the vicinity of the same peak, llichila. On the first 

 sorting-out of a quart-bottle of shells from this locality I placed 

 them together ; on a second sorting I noticed considerable differ- 

 ence in the sculpture when this was looked at under a high power, 

 combined with a modification in the form of the shell, of that inde- 

 finable nature one is so often confronted with in shells of this type. 

 Finally, on dissection, one (richilaensis) was found to be a Macro- 

 chlamys with the characteristic shell-lobes ; the other (hhutanensis), 

 above described, had none, and, besides, very different genitalia 

 with no amatorial organ, thus representing two quite distinct 

 genera. 



It will be interesting to see, when the land-shells of the Bhutan 

 Himalaya are better known, whether on this line of longitude, 88°, 

 we have entered the confines of a molluscan subregion distinct from 

 that to the west and south of it, one more closely related to that of 

 Western China. A Dafla form, of which I unfortunately had only 

 one badly preserved animal to examine, presented anatomical 

 characters differing very much from those we are well acquainted 

 with. Taking the external characters, the absence of a mucous 

 gland rendered it impossible to place it with certainty in any genus 

 wo at present know. This interesting species I describe further on. 



