20 ENDODOXTIDJE. 



JJ. Two transverse parietal plates. 



a. Shell flattened, no fold below umbilical angula- 



tion, umbilicus still narrower. Habitat, Ceylon, caliginosa. 

 1). Shell conoid, with a double fringe of curved 



hairs ; a horizontal fold below umbilical angu- 



lation ; umbilicus still narrower. Narrowest 



of all. Habitat, Ceylon biciliata. 



44. Ruthvenia retifera, Pfeiffer. 



Hdix retifera, Pfeiffer, P. Z. S. 1845, p. 73 ; Reeve, Conch. Icon, vii, 



1853, pi. 173, fig. 1170 ; ILinley & Theobald, Conch. Ind. 1874, 



pi. 87, figs. 8 & 9. 



Helix (Plectopylis ?) retifera, Nevill, Hand List, i, 1878, p. 70. 

 Helix (Plectopylis) retifera, Try on, Man. Conch, ser. 2, in, 1887, 



p. 161, pi. 34, figs. 63, 64. 

 Plectopylis retifera, Pilsbry, Man. Conch, ser. 2, ix, 1894, p. 146 : 



Gude, Science Gossip, x. s. iii, 1897, p. 301, fig. 43 (shell and 



armature). 

 Plectopylis (Sykesia) retifera, Gude, Science Gossip, N. s. vi, 1899. 



p. 149. 



Original description : " T. umbilicata, obtuse trochiformis, 

 striato-plicatula, lineis nonnullis concentricis elevatis reticulata, 

 carinata, diaphana, sericina, pallide cornea ; spira elevata, obtusa ; 

 anr'r. 6| planiusculi, ultiinus basi subplanus, striatus ; umbilicus 

 mediocris, pervius ; apertura depressa, securiformis ; perist. 

 simplex, acutum, margine supero brevi, basali plane arcuato. 

 " Diam. maj. 7, min. 6J, alt. 4 mill." (Pfeiffer.) 

 Hob. India : Nilgiris (Metcalf, Jerdon) ; Xoonoor Ghat (Blan- 

 ford,Nevill) ; Tinnevelly Hills (Beddome) : She vroy Hills (Blanford) ; 

 Mysore (Parry). 



Fig. 5. Ruthvenia retifera. 



The parietal armature consists of a single, strong, vertical plate, 

 slightly sinuate, but not notched, giving off a slight support 

 anteriorly a little below the upper extremity (see fig. 5 c, 

 which shows both the parietal and palatal armatures from the 

 posterior side). The palatal armature as in all the members 

 of the group is distinctly visible through the shell-wall, 

 and consists of two series of denticles, the upper series being 

 composed of : posteriorly, a strong, short, vertical flattened tooth, 

 and, anteriorly, a minute, horizontally elongated denticle, in a 

 line with the base of the posterior tooth ; the lower series is com- 

 posed of : posteriorly, a smaller, flattened, vertical tooth, and 



