PLECTOFYLiS. 93 



sixth bilobed or bisected about the middle, where a slight vertical 

 ridge connects their posterior portions ; the posterior portion of 

 the second fold is sinuous, somewhat S-shaped ; the third, fourth, 

 and fifth are slightly deflected posteriorly ; the sixth is very un- 

 equally bisected, the posterior portion being less than a third the 

 length of the anterior portion, which is raised at first and then 

 suddenly deflected (see fig. 39 g, which shows the inside of the 

 outer wall of the shell enlarged). The illustrations were made 

 from the type specimens in the collection of Lt.-Ool. G-odwin- 

 Austen, who kindly lent them for examination. Figs. 39 e-g 

 (enlarged), are taken from a specimen not quite full-grown ; 

 e shows the parietal and palatal armatures from the anterior 

 side ; / their posterior aspect, and g the inside of the outer wall 

 with its folds. This specimen exhibits the remains of a previous 

 parietal plate, one quarter of a whorl behind the permanent one. 

 Fig. 39 li shows the inside of the outer shell- wall of the specimen 

 depicted in fig. 39 d, the armature of which is incomplete, a 

 portion having been broken away. Two immature specimens in 

 different stages of growth exhibit armatures identical in all respects 

 with those illustrated, except that the palatal folds are less bilobed. 

 The species under consideration is allied to P. serica, but it 

 is larger, and presents considerable differences in the palatal 

 armature. 



89. Plectopylis serica, Godwin- Austen. 



Helix (Plectopylis} serica, God win- Austen, P. Z. S. 1874, p. 608, 



pi. 73, fig. 5 (shell and armature). 

 Helix sericata, Hanley & Theobald, Conch. Ind. 1875, pi. 132, 



figs. 8, 9. 

 Helix (Atopa (Plecfopi/lis)) serica, Tryon, Man. Conch, ser. 2, iii, 



1887, p. 159, pi. 34, figs. 49-52. 

 Plectopylis serica, Pilsbry, Man. Conch, ser. 2, ix, 1894, p. 140; Gude, 



Science Gossip, N. s. iii, 1897, p. 205, fig 1 . 31 (shell and armature). 

 Plectopylis (Chersaecid) serica, Gude, op. cit. vi, 1899, p. 148. 



Original description : " Shell dextral, very openly umbilicated, 

 discoid, pale horny brown, very flat above, with regular narrow 

 oblique bands of brown crossing the whorls. Epidermis thin. 

 The apex very slightly higher than the adjacent and outer whorls. 

 Whorls 7, narrow and closely wound, flat above, the last de- 

 scending near the aperture, which is diagonal ; outer margin cir- 

 cular ; peristome white, reflected, continuous on the body-whorl 

 or parietal margin. The palatal teeth, six in number, are situated 

 rather more than one-third the circumference from the aperture ; 

 and, counting from above downwards, the first is very minute, 

 the 4tb, 5th, and 6th largest. On the parietal side of the whorl 

 there is one single vertical lamina with short bifurcations or 

 supports above and below." (Godwin- Austen.) 



Major diam. 12-5, minor 11 mm.; alt. 4 mm. 



Hob. India : Hengdan and Kopamedza Ridge, 5,000 ft, Burrail 



