JONES & PRESTON: ON CHINESE AND BOENEA.N MOLLUSCA. 141 



15. Auricula aukis-Jud^ (Linn.). 



Plentiful in marshy places in British North Borneo, and in the 

 island of Labuan, and very frequently entirely decorticated. 



16. Auricula auris-Midje (Linn.). 



Somewhat less plentiful than the last, and found only in Labuan 

 Island. Like the former species, it is very often much decorticated, 

 and to obtain a specimen in good condition is not easy. 



17. Cassidula mustelina (Desh.). 



This species is plentiful in marshy places in Labuan. 



18. Cassidula auris-eelis (Brug.). 



Plentifully in association with C. mmtelina, Desh., Auricula miris- 

 Midce, and Auricula auris-Judce, in marshy spots in Labuan. 



It appears not improbable that the reason the loss of the perio- 

 stracum is so common in all these molluscs, is that they not infrequently, 

 when the tide falls, find themselves exposed to the full heat of the 

 tropical sun, in spite of the fact that they are very well able to bury 

 themselves in the mud. 



LlMN^A. 



Considering the profusion of Ziimicea elsewhere, and considering the 

 very unusual amount of suitable or apparently suitable ground for 

 the genus, the members of it are neither numerous nor widely dis- 

 tributed in China. In the neighbourhood of Hong Kong, where 

 a very large area has been minutely examined, there are only three 

 localities in which Limnace occur, all of which are separated by miles 

 of mountainous country fi'om one another, and in one instance, the 

 colony, one of L. Swifihoei, only amounted to a couple of dozen 

 specimens all told, and is situated on an island of small size. All 

 three areas are extremely limited in extent. 



In the Chusans also there is one limited area, sparsely populated 

 with Limncea plicatida. 



The most curious point about the distribution of the genus, as 

 regards the portions of China visited, is that it should be so abundant 

 on the Shantung seaboard, of all places physically the last in which 

 it might be expected to flourish. Yet every shallow sandy stream 

 in this part of the empire appears to produce a species or two. 



The Shantung coastline is, however, the resort, in Autumn and 

 Spring, of immense numbers of ducks and geese, travelling on migration, 

 and the great fondness of these birds for Li)nnce(B as articles of food 

 may perhaps account for the introduction of these molluscs in such 

 plenty, the egg-cases and young being carried on the legs or plumage 

 of the migrants. 



19. LiMN^A Mars, n.sp. Fig. 2. 



Shell narrowly acuminate, very thin, glossy, fulvous horn-colour, 

 very finely striated with lines of growth ; whorls 5 ; aperture inversely 

 auriform, about H of the whole height of the shell ; columella twisted, 



