32 



ENDODONTID.E, 



Original description: — " T. perforata, coiivexo-lenticularis, 

 tenuis, pellucicla, cornea, oblique plicata, biearinata : carinis pilis 

 longis ciliatis ; spira parum elevata, vertici subtili ; anfr. 4^ 

 sealares, ultimus aiitice non descendens, basi vix convexus ; 

 a])ertura subobliqiia, depresse secviriformis ; perist. simplex, 

 n^etura, niarginibus subparallelis, columellari vix reflexiusculo. 



" Diam. maj. 7|, miu. (H, alt. 31 mill." {Pfeiffer.) 



Hah. Ceylon (8Vmnei-); Hapiitale (C'o?Zgi;,) ; Patapoila (Preston). 



The systematic position of this species remained uncertain for 

 .H long time, the shell having been referred by various authors to 

 such different genera as Hemiplecta, Macrocldamys, and Kaliella. 

 In 1898, Mr. Sykes, in identifying some shells — collected by 

 Mr. Preston in Ceylon — as Helix biciliata, referred the species to 

 'Sykesia, a section of Plectopylis proposed by me in 1897 for the 

 reception of Helix clathratula and H. retifera. When classifying 

 all the known species of Pleciopylis in 1899, I stated that when 

 the anatomy of the forms referred to this section should come to 

 be investigated, they would probably be found to differ so widel}' 

 from typical Pleciopylis that the section would rank as a separate 

 genus. This has since been demonstrated to be the case by 

 Lt.-Col. Godwin-Austen, who has examined the animal of biciliata, 

 and has found, moreover, that it has close affinity with the 

 genus Thysanotu, placed, with some doubt, under Evlota by 

 Prof. Pilsbry, but \Ahich appears to pertain to the Eadodoatida;. 



Fis;. 10. — Buthvcnia hiciliata. 



The parietal armature consists of two simple obliquely ascendingf 

 folds, separated by a distance of half a whorl, having the upper 

 extremities somewhat attenuated and the lower truncate (see 

 tig. 10 d, which shows the parietal wall with its two folds). The 

 palatal armature is composed of : first, a short, horizontal fold 

 l:)elow the periphery, a little further back but in a line with it a 

 strong lamelliform denticle, ascending obliquely ; secondly, three 

 denticles in a line horizontally and about equidistant, the posterior 

 one strongest ; thirdly, a short slight horizontal fold near the 

 lower suture, rising near the aperture and revolving as far as the 

 second denticle {cf. fig. 10 e, which shows the inside of the outer 



