PLEGTOPYLIS. 129 



shorter horizontal lamella from the bottom ; the hinder with small 

 re-entering supports above and below. Beneath both is a narrow 

 free thread-like horizontal lamella. Palatal teeth 5 : 1st, 2nd, 

 3rd, and 5th horizontal, 4th vertical and stouter than the others ; 

 1st and 2nd longer than the remainder." (Blanford.) 



Major diain, 16, minor 13 mm. ; alt. 4*5 mm, 



Hob. Burma : Prome (Fedden, Blanford, Hungerford, Fea) ; 

 Thyet-Myo (Blanford}. 



111. Plectopylis cairnsi, Gude. 



Plectopylis cairnsi, Gude, Science Gossip, N. s. v, 1898, p. 171, 



fig. 90 (shell and armature). 

 Plectopylis (s. s.) cairnsi, Gude, op. cit. vi, 1899, p. 148. 



Original description : " Shell sinistrorse, discoid, solid, widely 

 urnbilicated, yellowish corneous, finely and regularly ribbed, and 

 decussated with microscopic spiral lines. Spire depressed, apex 

 scarcely prominent, suture distinctly impressed ; whorls 5|, 

 tumid above, rounded below, increasing slowly and regularly, the 



/ 9 



Fig. 64. Plectopylis cairnsi. 



last descending moderately in front ; aperture oblique, cordate, 

 a little inflexed at the upper outer margin. Peristome white, 

 strongly thickened and reflexed ; the margins united by a strong 

 raised flexuous ridge on the parietal callus, notched at the 

 junctions above and below. Parietal wall with a strong median 

 fold given off from the aperturai ridge, revolving round about 

 a quarter of the last whorl, but interrupted at the middle ; near 

 its posterior extremity occurs a branched fold in the form of the 

 Greek letter X, i. e. an obliquely ascending fold, having anteriorly 



