PLECTOPYLIS. 79 



80. Plectopylis macromphalus, Blanford. 



Helix (Plectopylis} macromphalus, Blanford, J. A. S. B. xxxix, 1870, 



p. 17, pi. 3, fig. 14; Godwin- Austen, P. Z. S. 1874, pi. 73, fig. 1 



(armature). 

 Helix macromphahis, Hanley & Theobald, Conch. Ind. 1874, pi. 83, 



figs. 8-10; Nevill, Hand List, i, 1878, p. 71 ; Tryon, Man. Conch. 



ser. 2, iii, 1887, p. 160, pi. 34, figs. 65-68. 

 Plectopylis macromphalus, Pilsbry, ibid, ix, 1894, p. 146; Gude, 



Science Gossip, N. s. iv, 1897, p. 10, fig. 46 (armature). 

 Plectopylis (Endothyra) macromphalus, Gude, op. cit. vi, 1899, p. 148. 



Original description: "Testa sinistrorsa, late umbilicata, de- 

 pressa, discoidea, tenuiuscula, pallido-cornea, superneplicisarcuatis 

 obliquis incrementi et liris spiralibus decussata, ad peripheriam et 

 subtus fere laevis, striatula ; striis nonnullis spiralibus circa uni- 

 bilicum aliquando distinguendis ; spira plana ; apice vix emergente ; 

 sutura leviter impressa. Anfr. 4|-5| planulati, arete voluti; 

 ultirnus vix latior, supra peripheriam sub-augulatus, ad latus atque 

 subtus convexus, antice leviter descendens. Apertura irregulariter 

 lunaris, superne compressa, diagonalis ; peristoma albido-labiatum, 

 parum incrassatum, reflexiusculum, inarginibus convergentibus, 



a 

 Fig. 29. Plectopylis macrompkalus. 



callo tenui junctis, externo supra peripheriam areuato. Plicatio 

 interna persimilis ei Helicis pinacis et H. plectostomatis ; e 

 lamina unica parietali, verticali et plica tenui longuiscula basali, 

 atque plicis 5 palatalibus : basali tenui simplici, ceteris duplicibus, 

 constans. 



"Diam. maj. 6|, min. 5|, alt. 2f mm." (Blanford.} 

 Hal. Assam: Mairung, Khasi Hills ( Godwin- Austen) ; Dafla 

 Hills (Godwin-Austen) ; Naga Hills (Chennell). 



The parietal armature (see fig. 29 a) consists of a strong vertical 

 plate, which has a minute, slightly elongated, horizontal denticle 

 posteriorly to its lower extremity. The palatal armature is in two 

 series (see fig. 29 6, which shows the inside of the outer wall). 

 The anterior series is composed of four short, broad, flattened, 

 straight horizontal folds. The posterior series consists of six 

 narrow horizontal folds, which are shorter than those of the 

 anterior series ; the fourth and fifth are a little obliquely de- 

 pressed posteriorly. The specimen is in Mr. Ponsonby's collec- 

 tion, and measures 6 millimetres in diameter. Two specimens 

 in my collection also measure 6 millimetres in diameter. 



