COLLINGE : NON-OPERCULATE LAND AND FRESHWATER MOLLUSCS. 87 



different. As yet our knowledge of the internal structure of this genus 

 is very imperfect. I have given a very brief account of the anatomy of 

 Apera hurnupi, E. A. Smith (3), and A. natalensis, Cllge. (5), from 

 two alcoholic specimens, and in a later example of the former species, 

 I have recently figured and described the male organ (7). This figure 

 is repeated here for comparison (PI. vi, fig. 6). 



An examination of the specimens contained in ihe present collection, 

 and comparison with the results obtained by the above authors, suggests 

 not a few points of interest. 



Firstly there seems every probability that the family RaflwuUiidae 

 comprises a large number of species, and possibly genera, distributed 

 over the Malay-Australian region and Southern China. 



From the primitive condition of the digestive organs, and similar 

 indications in the generative organs, I am adverse to grouping any of 

 the genera with the I'estacelUdae, and prefer to regard the Testacellid 

 resemblences as a case of parallel evolution rather than one of direct 

 affinity. 



Respecting the generic or sub-generic distinctiveness of liafJwuifiia, 

 Afopos, Prisma, and Padamjia, our knowledge is yet too inexact and 

 insufficient for any definite expression of opinion. I agree with the 

 Sardsins that Prisma, Simr., is as yet insufficiently defined, still, I think 

 there can be no doubt as to the wisdom of separating it from Afo})Ox 

 on the one hand and Veronicplla on the other. 



From the above brief resume it will be seen that we have yet much 

 to learn respecting the internal structure of these most interesting 

 molluscs, before our attempts at classification or tracing affinities can 

 be of any value. I am pleased to learn that my friend Dr. Josef F. 

 Babor has in active preparation a monograph of the genus Atopos, to 

 the completion of which, all malacologists will look forward with great 

 interest. 



RATHOUISIIDAE, Hei.de. 



Atopidae,\'on\\\tnng: Nachr. Deutsch. Malak. Gesell., 1892, p. 143. 

 Atopos, Sinir. 



Atopos sapasini, n. sp. 



PI. V, figs. 40-42, 56-59, PI. vi, figs. 60-65. 



Colour of the notum a deep blue, granulated, extending over the 

 head in a hood-like manner ; head yellowish ; underside (perinotum ?) 

 yellowi>h-brown ; foot-sole yellowish-brown ; keel only faintly produced. 

 Length of notum (in alcohol) 59'5, breadth i3'5, height i4"5 millim. 

 Breadth of foot-sole 9 millim. Female generative orifice 14 millim. 

 from the male generative orifice. 



