1888.] MOLLUSCA FROM BURMAH. 243 



oblique, semilunate ; peristome strong ; columellar margin very- 

 oblique. 



Size: maj. diam. 12-2o, min. 11-20, alt. axis 5-0, body-whorl 

 6 '.5 mm. 



This shell belongs to a group common in Arakan &c. {E. pansri, 

 helicifera, ataranensis, mammillaris) , but is of a more depressed 

 form and larger in size, smooth below and well sculptured above ; 

 E.falcata is a large representative of the group in the Khasi Hills. 



10. Helix (Plectopylts) ponsonbyi. 



Locality. Hlindet, Upper Burmah, 1.500 feet. 



Shell sinistral, widely umbilicated, discoid, solid ; sculpture, wavy 

 thread-like lines of growth; colour pale brown; spire flat, 2| 

 whorls at apex slightly raised above the succeeding whorls ; suture 

 very shallow ; whorls 7, closely wound and flat ; aperture very 

 obhque, descending, horizontally ovate ; peristome thickened, re- 

 flected, the margin connected by a well-developed ridge, and with 

 sHght notches at the inner angles. 



Size: maj. diam. 17*5, min. 14-0, alt. axis 5 mm. 



Palatal teeth 6, the 1st highest, long, thin, like a knife-edge, the 

 2nd and 3rd are short and rounded above, the 4th and 5th are 

 united ; the 6th, situated on the lower outer side of the body-whorl, is 

 short, somewhat thickened and rounded on the free edge. The 

 parietal vertical laminae are two in number ; the anterior situated 

 about 10 millim. from the inner margin of the peristome. The 

 anterior one is curved, solid, arched above, with two short buttresses 

 above and below on the anterior side. The posterior one is obliquely 

 set, is thin, and of nearly even height throughout. 



The horizontal parietal lamina is only present as a short and 

 narrow ridge 3 millim. in length, situated just within the aperture, 

 but not connected with the apertural ridge of the peristome ; a thread- 

 like, free, narrow, horizontal lamina, commencing from below the 

 posterior vertical lamina, extends forwards towards the aperture, 

 gradually fining out but not extending to it. 



To the ordinary observer the shell would only possess the one 

 simple short ridge near the peristome, all the other complicated 

 structure being out of view so far back within the aperture. 



11. Helix (Plectopylis) perarcta, W. T. Blanford. 



ioca%. Hlindet, 1200 feet. 



Size : maj. diam. lO'O, min. 8"0, alt. axis 3*5 mm. 



The type of this species came from near Ava. In this specimen 

 the horizontal lamina is continuous to the aperture, in others it is 

 sometimes undeveloped for a short distance {vide P. Z. S. 1874, 

 pi. Ixxiv. f. 4). 



12. Streptaxis thebawi, n. sp. 



Locality. Pingouns:, Shan Hills, 2.500 feet. 



Shell ovately globose, umbilicated, somewhat solid ; sculpture 

 finely costulated throughout ; colour white ; spire conical, apex 



