764 GASTROPODA. [Pulmonata. 



on the lower^whorls ; the apical whorls usually denuded and flesh- 

 coloured ; peristome white, aperture purplish-red within ; a whitish 

 narrow subsutural border is sometimes present, but it is much less 

 conspicuous than in P. Hongii, and very often wanting. Epidermis 

 thin, brown, slightly shining. Spire elevated conic, with a very 

 blunt apex, 1^ to liy times the height of the aperture ; outlines very 

 slightly convex. Protoconch of 3 convex whorls, the nucleus with a 

 raised inner carina. Whorls 6^, the first few but little descending, 

 lightly convex ; base flatly rounded. Suture not deep, somewhat 

 uneven, margined below on the lower whorls. Aperture vertical, pyri- 

 form, angled above, broadly rounded and somewhat angled toward 

 the pillar below. Peristome continuous. Outer lip not expanded and 

 not much thickened, rounded and smooth, rarely with very slight 

 indications of denticles within. Basal lip slightly expanded, smooth 

 or with a few indistinct notches. Columella oblique, lightly concave, 

 indistinctly folded above. Inner lip not broad, with a well-marked 

 rim forming the continuation of the basal lip ; veiy rarely a few small 

 tubercles may be found on the lower part of the parietal wall, but 

 usually it is quite smooth. The umbilical fissure is always small. 



Diameter, 40 mm. ; height, 91 mm. (type). Diameter, 43 mm. ; 

 height, 99 mm. (largest specimen). 



Egg and Embryonic Shell. The egg is very large, elongately regu- 

 larly oval, rounded at both ends, calcareous, thin, white, finely granular, 

 with a few larger granules irregularly interspersed. Length, 18 mm. ; 

 diameter, 13 mm. The embryonic shell, of- 3^ whorls, is axially finely 

 ribbed, and on the upper half of the last whorl the riblets are decus- 

 sated by fine spiral hree. There is a distinct narrow and open um- 

 bilicus. Diameter, 12mm.; height. 17 mm. 



Jaw arcuate, attenuated at the ends, irregularly striated by m- 

 foldings of the membrane. 



Radula tongue-shaped, of about 130 transverse rows of teeth, 

 which are nearly straight, forming a very obtuse angle, salient pos- 

 teriorly. Formula of radula 20 + 30 + 1 + 30 + 20. The central 

 tooth elongated, with a long and b.oad mesodont and a low and broadly 

 rounded mesocone ; usually there are 2 minute side cusps present. 

 Lateral teeth, numbering about 30, with a very broad rounded meso- 

 dont, the mesocone short and broad ; there is no endodont, but the 

 ectodont is distinct, narrowly rounded, bearing a minute cutting- 

 point. The marginals are narrower, and with 2 cutting-points ; to- 

 wards the margins they are becoming very narrow and indistinct, and 

 it is impossible to exactly ascertain their number. 



Reproductive Organs. -The male organ is very large, with the re- 

 tractor muscle at its apex, and the walls very thick. The vas deferens 

 enters near the apex, and it is free only for a very short distance at the 

 base. The albumen-gland is large. The most remarkable feature is 

 the absence of a receptaculum seminis, which is present in P. Hongii. 



