112 LAND AND FRESHWATER 



slight indication of keel, rounded near aperture ; aperture roundly 

 lunate, suboblique ; peristome thin, perpendicular at the columellar 

 margin, well reflected. 



Size : maj. diam. 2-5 ; alt. axis 1"4 mm. 



Taken off the trunk of a mango-tree in very wet weather, July 

 1896, together with a species of KalieUa. 



I at first identified this shell as A', delectahills, Sykes, but the 

 sculpture is transverse and very difi^erent. (See and compare 

 drawing of this, fig. 4.) 



Animal. Very pale-coloured. The eyes in the spirit-specimen 

 (apparently) on very short blunt tentacles (fig. 3 c) ; from the posi- 

 tion of the eye, contracted, they could not be long in life. The foot 

 is divided with a pallial line ; sole of foot rounded behind and trun- 

 cate, with a mucous gland apparent. 



The generative organs were not in a state to be made out ; no 

 amatorial organ appeared present, nor could I, in the three speci- 

 mens dissected, find the jaw. 



The radula (fig. 3 e) is extremely small, and the form of the 

 outer teeth very diflicult to make out ; they are tricuspid, like those 

 of KalieUa. 



25 . 1 . 5 . 1 . 5 . 1 . 25 



31 . 1 . 31 



The animal is ovo-viviparous. There were four young in the uterus 

 (fig. 3/), three with the shells well developed in two specimens I 

 examined ; these embryonic shells are 0-0 to 0-7 mm. in diameter 

 of Ig wliorls, and the rough decussate surface is already well 

 seen. In this early stage of growth (fig. 3 /;) the eyes (e) are con- 

 spicuous, and the foot (/) well developed and extruded at the 

 aperture. In one, two tubes (x) -were discerned close together, one 

 larger than the other, which, from their position, would indicate 

 the early formation of the anal and respiratory organs respectively. 



Extending from both eyes backward was a long filamentary 

 agglomeration of dark particles or pigmented cells, ending gradually 

 in a point (rm), which I take to be the retractor muscles of those 

 organs in coarse of development. The apical portion of the shell 

 was filled with a large cellular mass, which would in this place 

 correspond to the mature liver. In better-preserved specimens the 

 gradual development of the series would be an interesting study up 

 to the final exit of an individual able and ready to crawl about and 

 feed itself. 



I am in great doubt as to the position of this species and place it 

 for the present in Microcystis. Considering the similarity of the 

 radula to that of KalieUa, we should try to learn something more of 

 the early stages of development in that genus and com]>are the form 

 of the adult animal. The embryonic development is similar in this 

 Ceylon form to the (Oahu) Sandwich Island Microcystis ? halclwini, 

 Ancey, which I have dissected and described for Mr. Sykes. Semper 

 also shows that Microcystis myojis of iiasilim has a similar ovo- 

 viviparous habit (Ileis. Philipp. iii. p. 43, pi. iv, fig. 9). Physical 



