MOLLTJSCA OF INDIA. 



59 



the Indian region, I should certainly have done the same ; yet the 

 animal differs from that genus, not in one but in several characters 

 —externally in the absence of the long shell-lobes ; internally in 

 the odontophore and jaw ; and in the reproductive organs it is 

 widely separable, MacrochIami,s not possessing the sincida amoris 

 a e of the calcareous type). In searching through Semper's work for 

 characters approacliing those now figured and described, I observe 

 the nearest, as might be expected, in those genera found in the islands 

 of the Malay Archipelago, and not in those found to the westward 

 ia India. On plate iii. figs. 1 & 2, Reise im Archipel d. Philipi)., is 

 shown the sagitta amator-ia of Tennentia philippinensis and Par- 

 marion pupillaris from Java of the same type. This I would 

 submit is an indication that the slug-like forms of this part of the 

 world are the descendants of these glassy Helices, just as we find 

 the general anatomy of Gmma, a slug-like species of India, to be 

 like that of Macrochlamys, and that although the outward form of 

 both animal and shell is very similar respectively, the races of the 

 two areas have a most remote relationship. How far these cha- 

 racters of Everettia and Dyalia extend around this area is yet to be 

 discovered. We cannot as yet say with certainty that shells with 

 similar internal structure do not exist in India ; they are certainly 

 absent in the N.E. Himalayas and Khasi Hill Ranges, but there 

 are numbers of even large species in Southern India and Ceylon 

 yet to be examined, and of which we know as yet nothing. Of the 

 shells of New Guinea we are also quite ignorant,^ at least I have 

 not seen any work on their anatomical variations." 



I have since then been able to obtain, through the kind aid of 

 Dr Thurston of the Madras Museum, several species from that 

 neighbourhood and the Nilghiri Hills ; they all present common 

 characters very different to those of the Bornean species mentioned 

 above. Finally in 1895, in the joint paper on Bornean molluscs, 

 quoted before, the following paragraph concludes it :— "It seems to 

 us that there can be little doubt but that the slug-hke forms of 

 Borneo have the same close relationship to the shell-bearing molluscs 

 among which they are now found living, as the Indian forms bear 

 to Macrochlmmjs and allied shell-bearing genera, and any true 

 attempt at classification must be based on these lines, and would 

 place a wide gulf between Girasia and Austenia on the one side, 

 and Parmarion and Microparmarion on the other. Further, we 

 think that future research will clearly show that many of the slugs 

 cannot rightly be placed in families by themselves, but will find 

 their true position before or after the genera they have descended 

 from or developed into." 



Since this was written, Mr. AV. CoUinge has recently read a paper 

 at the Zoological Society giving descriptions of two other species of 

 Parmarion from Lombok, Borneo, presenting specific differences 

 of interest from those molluscs we before described. Neither 

 depart from the Parmarion structure. The darts were not satis- 

 factorily made out, and the lingual ribbon was not included in the 

 descriptions. In P. everetti the s^vcida amoris was in all probability 



