110 



HELICIDjE. 



the lower suture. The free horizontal plate has not yet been 

 formed. About 3 mm. behind the vertical parietal plate is found 

 the remnant of a previous barrier, almost absorbed. The palatal 

 folds are similar to those of mature specimens, but the second is 

 not bifurcate. 



99. Plectopylis dextrorsa, Benson. 



Helix {Plectopylis) rcfwja, var. dextrorsa, Bensou, A. M. N. H. 



ser. .3, V, 1860, p. 4.' 

 Helix refiiga, var. dextrorsa, Hanley & Theobald, Couch, lud. 1870, 



pi. 13", fig. 9. 

 Helix (Atopa (Plectopylis)) refuqa, var. dextrorsa, Trj'ou, Man. 



Conch, ser. 2, iii, 1887, p. 104, pi. 35, fig. 2. 

 Helix (Plectopylis) dextrorsa, Godwin- Austen, P. Z. S. 1875, p. 44. 

 Plectopylis dextrorsa, Pilsbry, Man. Conch, ser. 2, ix, 1894, p. 145 ; 



Gude, Science Gossip, n. s. iii, 1896, p. 156, fig. 21. 

 Plectopylis (Chersaecia) dextrorsa, Gude, op. cit. vi, 1899, p. 148. 



Original descrijyiion : — " Januapliciformi fauciali prima remota; 

 lamina 1 parietali magna verticali simplice antice lamellam 1 in- 

 feriorem elongatiusculam eniittente, lamella superioi*e valde 

 elongata aperturse laminam parietalem non omnino attingente, 

 plica basali obsoleta; plicis palatalibus intrantibus 6, tribus 

 superioribus et basali elongatis siiuiosis, quarta et quinta brevibus, 

 postice plicis obliquis distinctis munitis." (Benson.) 



Major diam. 17, minor 14 mm. ; alt. 5 mm. 



Bab. Lower Burma : Phye-than, Tenasserim Valley (Benson). 



Oi'iginally described by Benson as a variety of P. reftiga, it was 

 raised to specific rank by Lt.-Col. Godwin-Austen in 1875, who 

 stated that it was very close to P. vseudoplds [^ = leiophls\ but his 



Fig. 52. — Plcetojyylis dextrorsa. 



figure of that species— copied ante p. 101, fig. 4G — does not bear 

 out this view, and after careful comparison I came to consider its 

 nearest ally to be P. brachij discus. The shell, however, is smaller 

 than in that species, measuring 16 millim, in diameter, and there 



