SCIENCE-GOSSIP. 



180 



specimen is of special interest from possessing, in 

 addition to the mature plates, the remains, partly 

 absorbed, of the previous set, consisting of the 

 basal portion of the parietal plate, the whole of the 

 first palatal fold, parts of the second and fourth, 

 and the whole of the fifth and sixth, with the 

 adjacent tooth. Here we have, therefore, absolute 

 proof of the absorption of the earlier armature as 

 suggested in the case of Corilla. 



The Rev. Vincenz Gredler described a variety of 

 this species under the name of P. fimbriosa var. azona 

 (Jahrb. Deutsch. Malak. Gesells, xiv. (1887), p. 369), 

 which, subsequently, he raised to specific rank 

 (" Nachrichtsblatt der Deutschen Malakazoolo- 

 gischen Gessellschaft," xxi. (1889), p. 155). In order 

 to ascertain whether any difference in the armature 

 could be detected, I have opened the single speci- 

 men in my collection (from Patong, West China), 

 but with the exception of the tooth near the sixth 

 palatal fold being absent and the palatal folds 

 generally being a little shorter, it is identical, and I 

 am, therefore, of opinion that this form must be 

 regarded as a variety, as originally suggested by 

 Mr. Gredler. It is smaller than the type, measur- 

 ing only 12 millimetres in diameter, a little 

 darker and less shining, and it is devoid of the 

 yellowish zone round the umbilicus, so that the 

 varietal name suggested is very appropriate. Dr. 

 von Mcillendorff has named a variety nana, which 

 differs from the type in having the last whorl with 

 a more acute peripherial angle and in being much 

 smaller, the measurement given being 6 milli- 

 metres. I do not know this variety, and have, there- 

 fore, had no opportunity of studying its armature. 



Pledopylis pulvinaris (fig. 25) was described by 

 Dr. A. A. Gould in the " Proceedings of the Boston 

 Society of Natural History," vi. (1859), p. 424, 

 from specimens collected in Hong Kong and in 



Fig. 2^.-I'lectopyUs pulvinaris. 



China, near Canton. It was also collected in 

 Hong Kong by Dr. von Martens, who figured the 

 species in " Die Preussische Expedition nach Ost- 

 Asien," Zoologischer Theil, ii. (1867), t. 14, f. 9, 

 and this figure has been copied by Mr. G. W. 

 Tryon in his "Manual of Conchology " (2), iii. 

 (1887), t. 33, ff. 29-31. It was likewise figured 

 by Dr. von Mollendorff in the " Jahrbuch der 

 Deutschen Malakazoologischen Gesellschaft," x. 

 (1883), t. 12, f. 9, and by Dr. W. Kobelt in Martini 

 und Chemnitz' " Conchylien Cabinet," ii. (1894), t- 

 205, ff. 12-14. The shell is disk-shaped, widely per- 

 spectively umbiHcated, pale corneous brown, com- 

 posed of six closely regularly coiled whorls, finely 

 striated above with very minute spiral sculpture 

 scarcely visible under a strong lens ; the spire is 



almost flattened, with the apex a little raised ; the 

 last whorl widens toward the aperture and is 

 a little defiexed in front. The armature consists 

 of a strong lunate vertical plate on the parietal 

 wall, strongly deflexed posteriorly, the convex side 

 towards the aperture, with two short horizontal 

 teeth on the anterior side, one above and one 

 below, in a line with the two extremities, the 

 upper being the stronger of the two. The 

 palatal wall bears seven horizontal folds ; the 

 first thin, near to and parallel with the suture, 

 the second, third, fourth, and fifth, larger 

 and stronger than the first, almost parallel 

 to each other, equidistant and descending a little 

 obliquely posteriorly ; the sixth smaller and 

 parallel with the lower suture. There are in 

 addition, behind the principal folds, two small 

 teeth, one in a line with the fifth fold and more or 

 less connected with it, the other midway between 

 the fifth and sixth folds. The second fold is a 

 little indented posteriorly so that a separate 

 denticle is almost formed. The specimen figured 

 is from Hong Kong, and measures 16 millimetres 

 in diameter. A specimen in Mr. Ponsonby's 

 collection is larger, measuring 22 millimetres 

 in diameter ; the shell is darker, thicker, rugosely 

 striated, and the spiral sculpture is more 

 decided ; the whorls are more tumid and the 

 peristome is much more reflexed and thickened, 

 while the margins are connected by a whitish 

 callus which bears a slight denticle. This 

 specimen probably belongs to P. pulvinaris var. 

 continentalis, described by Dr. von Mollendorff 

 (Jahrb. Deutsch. Malak. Gesells. xii. (1885), p. 

 388), from Canton. The shell figured by Dr. 

 Kobelt (op. cit.) bears a similar denticle on the 

 parietal wall. Mr. H. Fulton has obligingly sent 

 me for examination, ten specimens of this species, 

 the smallest of which measures 16 millimetres, 

 and the largest 20 millimetres in diameter ; of 

 these, five, including the smallest and the largest, 

 possess the denticle on the parietal callus, and two 

 more have a rudimentary denticle. 



Plectopylis cutisculpta (figs. 26a-c), from Fud-Shien, 

 was described by Dr. von Mollendorff, in the 

 " Jahrbuch der Deutschen Malakazoologischen 

 Gesellschaft," ix. (1882), p. 184, and figured by 

 him in the same work, x. (1883), t. 12, f. 12. The 

 shell is disk -shaped, with the spire a little raised 

 and composed of six or seven slowly increasing 

 whorls, finely ribbed above, smooth and shining 

 below ; the last whorl scarcely descends in front, 

 the umbilicus is wide and open, and the peristome 

 is a little reflected, the specimen figured measures 

 7 millimetres in diameter. The parietal armature 

 consists of a strong vertical plate, a little convex 

 towards the aperture, with a slight angular callosity 

 anteriorly at the lower extremity, and with a little 

 ridge above and below posteriorly ; on the posterior 



