32 BNDODONTID^E. 



Original description : " T. perforata, convexo-lenticularis, 

 temits, pellucida, cornea, oblique plicata, bicannata : carinis pilis 

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

 scalares, ultimus antice non descendens, basi vix convexus ; 

 apertura snbobliqua, depresse securiformis ; perist. simplex, 

 rectum, margiriibus subparallelis, columellari vix reflexiusculo. 



" Diam. maj. 7j, min. 6J, alt. 31 mill." (Pfeiffer.) 



Hab. Ceylon (Skinner) ; Haputale ( Collett) ; Patapoila (Preston). 



The systematic position of this species remained uncertain for 

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

 such different genera as Hemiplecta, Macrochlamys, 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 Plectopylis 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 widely 

 from typical Plectopylis 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 Thysanota, placed, \vith some doubt, under Eulota by 

 Prof. Pilsbry, but which appears to pertain to the Endodontidce. 



Fig. IQ.Buthvenia biciliata. 



The parietal armature consists of two simple obliquely ascending 

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

 extremities somewhat attenuated and the lower truncate ^see 

 fig. 10 c, which shows the parietal wall with its two folds). The 

 palatal armature is composed of : fir*t, a short, horizontal fold 

 below the periphery, a little further back but in a line with it a 

 strong lamellit'orm denticle, ascending obliquely; secondly, three 

 denticles in a line horizontally and about equidistant, the posterior 

 one strongest; thirdly, a short slight horizontal told 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 



