282 ZONITID^. 



descending ; aperture much lower than in T. comjiluvialis, 

 eolumellar margin of peristome oblique. 



Major diam. 11, min. 10, height 5 mm. 



Hab. South Andaman, Port Blair. 



[The animal of Taphrosjnra hathycharax, Bs. MS., a close ally 

 of T. convallata, Bs., from the South Andaman Island, is as 

 follows : — 



Animal ochraceous, dark grey on the extremity of foot ; mucous 

 gland overhung by a pointed termination. Sole of foot divided ; 

 usual peripodial grooves with a broad margin below. 



The right shell-lobe is long and fairly broad at base, and in life 

 probably very extensible over the shell. The left shell-lobe is 

 very broad and smooth and must spread over a large surface of 

 the shell. The dorsal lobes are all small, the left in two parts, 

 the posterior situated under the left shell-lobe and distant from 

 tii.e anterior lobe. The wall of the branchial chamber is sparsely 

 spotted. The animal examined was in an excellent state of preser- 

 vation, the generative organs at their full maturitj'". The most 

 notable thing is the absence of the amatorial organ. The penis 

 is elongate, there is a short kale-sac contiguous to the junction 

 of the vas deferens, followed by a moderately long epiphallus, up 

 to the penis, nniscle retractor ; there is no cascum, the tube bends 

 on itself and soon expands into a convoluted mass with an indis- 

 tinct coiled appearance when looked at with transmitted light, 

 thence it becomes much narrower and leads away towards the 

 generative aperture. The above swollen aperture looks as if we 

 had here the representative of the coiled caecum of Macrochlamys 

 much modified and separated from the retractor muscle. The 

 spermatheca is elongate, and contains three spermatophores 

 beautifully preserved ; the walls of the sac were of necessity much 

 stretched and transparent. The uterus and ovo-testis do not call 

 for any attention. 



The spermatophore recalls that of Austenia r/ir/as. The flume 

 is very long with a bunch of fine bifid delicate spines at its basal 

 end ; for about two-thirds of its length it is straight-edged and 

 spineless, six spines then occur at very equal distances apart, up 

 to the junction of the flume and capsule, which is long and 

 cylindrical, terminating in a thin whip-hke appendage, but the 

 cap-like end of the capsule seen in other species is not present in 

 this one. The most striking feature of this spermatophore is 

 the large single antler-like process at the terminal end of the 

 flume, having six points, and these again bifid, very similar in this 

 respect to A. gigas. 



Jaw semicircular, with a central projection. 



The radula formula is 



+ 18. 2. 9. 1.9. 2. 18-1- 

 + 29 . 1 . 29 -I- 



Central tooth tricuspid, admedians bicuspid, of usual form in 

 MacrocJdamys.~\ 



