PLECTOPTLIS. 75 



C. Parietal plate ramified. 



a. Shell acutely keeled. Parietal fold trifurcate; a 



short horizontal fold near aperture cyclaspis. 



b. Shell not keeled. Parietal fold trifurcate. 



. No horizontal fold below parietal plate, a free 



interrupted horizontal fold in front cairnsi. 



/3. Parietal fold giving off anteriorly an interrupted 

 horizontal fold ; a short horizontal fold below 



plate lintcrcc. 



y. Parietal fold giving off anteriorly a continuous 

 fold. 



* Shell thin karenorum. 



** Shell thick. 



t Upper arm of parietal fold longest, lower 



horizontal fold united to apertural ridge . repercmsa. 

 ft Lower arm longest, lower horizontal fold 



not united to apertural ridge. 

 Whorls much flattened, umbilicus very 



shallow anyuina. 



Whorls less flattened, umbilicus deeper . bensoni. 



I. Section ENDOTHYRA, Gude. 

 Endothyra, Gude, Science Gossip, N. s. vi, 1899, p. 148. 



Sinistral. Umbilicus moderate. Palatal folds horizontal or 

 oblique. 



TYPE, Helix (Plectopylis} plectostoma, Benson. 

 Range. Sikkim, Assam, Burma. 



77. Plectopylis minor, Godwin- Austen. 



Helix (Plectopylis} minor, Godwin-Austen, A. M. N. H. ser. 5, iv, 



1879, p. 164 ; ibid., J. A. S. B. Ixiv, 1895, pi. 7, fig. 3 (shell and 



animal). 

 ? Helix (Plectopylis) macromphalus, var. minor, Blanford, J. A. S. B. 



xxxix, 1870, p. 18. 

 Plectopylis minor, Gude, Science Gossip, N. s. iv, 1897, p. 11, fig. 47 



(shell and armature). 

 Plectopylis (Endoihyra) minor, Gude, op. cit. vi, 1899, p. 148. 



Original description : " Shell sinistral, openly umbilicated, dis- 

 coidal, hirsute. Sculpture coarse, with irregular transverse 

 ribbing; colour pale umber, with regularly disposed broadish 

 transverse bars of sienna brown; spire flat, only the first three 

 whorls slightly rising above the others ; suture shallow. Whorls 5, 

 subangular on the periphery of the last, which has four distinct 

 rows of short hairs, entire at the point. Aperture oblique, slightly 

 descending ; peristome lunate, slightly flattened on the upper 

 outer margin, but very little reflected, the inner margins connected 

 with a distinct ridge on the parietal side. 



