98 HELICID^E. 



callus with a raised flexuous ridge slightly notched at the junctions 

 above and below. 



" Parietal armature (fig. 43 6) composed of a vertical plate, 

 deflexed posteriorly above, with a short obliquely ascending ridge 

 below, projecting on both sides ; a long horizontal fold rises a 

 short distance from the vertical plate, running parallel with the 

 whorl and joining the raised ridge at the aperture ; below this 

 occurs a second, but very short fold, 2 mm. long, also rising 

 close to the vertical plate and in a line with its lower extremity ; 

 below the vertical plate runs a third, but very thin and slight 

 horizontal fold close to the lower suture and joining the ridge at 

 the aperture. The palatal armature (fig. 43 a) consists of : first, 

 a thin bilobed horizontal fold near the upper suture ; next, two 

 horizontal rather thin elevated folds, followed by two stouter 

 and rather less elevated folds, obliquely ascending towards the 

 mouth ; and lastly, a thin horizontal fold near the lower suture, 



Fig. 43.Plectopylis Jccngtungensis. (From Proc. Malac. Soc. London.) 



longer than the others and gradually attenuated anteriorly ; all, 

 except the first fold, are provided posteriorly with a slight 

 denticle, while a low transverse ridge unites their posterior 

 terminations. Fig. 43 c gives the posterior view of the parietal 

 and palatal barriers." (Gude.) 



Major diam. 12, minor 10, alt. 4'75 mm. 



Hob. E. Burma : Kengtung (Woodthorpe). 



Three specimens in the Godwin-Austen collection, British 

 Museum, were found upon examination to be closely allied to 

 P. nagaensis, G.-A. The new species, however, is more depressed 

 and lacks the spiral sculpture of its ally which also has the 

 barriers placed nearer the aperture, and the third, fourth, and 

 fifth palatal folds more oblique, while Icengtungensis possesses a 

 short horizontal median fold which is absent in nagaensis. It also 

 resembles P. muspratti, Gude, in having the palatal folds united 

 posteriorly by a low ridge and in having the barriers at the same 

 distance from the aperture, but in the latter species the palatal 

 folds are much shorter and stouter and it lacks the long horizontal 

 parietal fold as well as the short median fold, being only provided 

 with a short fold at the aperture. 



