SCIENCE-GOSSIP. 



II 



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 depressed posteriorly. The 

 specimen is in Mr. Ponsonby's collection, and 

 measures 6 millimetres in diameter. Two speci- 

 mens in my collection also measure 6 millimetres 

 in diameter. 



Plectopylis minor (figs. 47^-/), from Darjeeling, was 

 described by Lieut. -Colonel Godwin-Austen in the 

 "Annals and Magazine of Natural History" (5), 

 iv. (1879), p. 164. As the species has never, to my 

 knowledge, been figured, I have much pleasure in 

 illustrating it. Mr. W. T. Blanford mentioned a 

 var. minuy of Plectopylis niacromphalus in the 

 " journal of the Asiatic Society of Bengal," .\xxix. 

 (1870), part 2, p. iS, which is probably the same 

 form. The shell is sinistral, openly umbilicated, 

 discoid, hirsute, finely ribbed, decussated by spiral 

 lirae above, pale corneous with equidistant trans- 

 verse brown striae; the spire is a little raised, the 

 suture impressed. There are five regularly coiled 



^ L^M 



Mj 



Fig. 47. — Plectopylis minor. 



whorls, the last being sub-angular at the periphery^ 

 a little wider than the preceding whorl and a little 

 descending in front. The cuticle is produced into 

 distant, transverse, brownish, raised plaits, which 

 are each provided with four coarse, deciduous 

 hairs, forming four lines which pass round the 

 body whorl. The aperture is lunate, flattened on 

 the upper outer margin, and a little oblique. The 

 peristome is white, a little thickened and reflexed ; 

 the margins are connected by a slightly raised 

 ridge on the parietal callus. The umbilicus is 

 moderately deep and wide, but narrower than in 

 Plectopylis mMyomphdus. The parietal armature 



consists of a strong vertical plate, a little deflexed 

 below anteriorly, having posteriorly two minute 

 denticles, one above and one below. A very thin, 

 free horizontal fold occurs below the vertical plate, 

 revolving as far as the parietal ridge at the 

 aperture, where it becomes much attenuated (see 

 fig. 47/.) ; this fold appears to be somewhat 

 variable, for in a specimen in Mr. Ponsonby's 

 collection, shown in fig. 47/, it is very short, 

 and scarcely extends beyond the vertical plate ; 

 while in another specimen, also in Mr. Ponsonby's 

 collection, shown in fig. 471?, it is absent 

 altogether. Lieut. -Colonel Godwin-Austen, in his 

 description of the species, states: "Parietal vertical, 

 lamina simple, with no distinct horizontal plica 

 below it." 



The palatal armature is in two series, the 

 anterior series consists of four thin horizontal 

 folds, and the posterior series of six horizontal 

 folds, the first of which is very minute, the next 

 four a little broader and shorter than those of the 

 anterior series, the fourth and fifth a little deflexed 

 posteriorly, and the sixth very small and thin (see 

 figs. 47^"). The specimen shown in figs. 47^-^ is 

 in Mr. Ponsonby's collection, and measures— major 

 diam., 5 millimetres; minor diam., 4 millimetres; 

 alt. 2-5 millimetres. The one shown in figs. 

 47/ and g is in my collection, while that shown 

 in figs. 47/?-/ belongs to Mr. Ponsonby, who 

 informs me that it was obtained from Mr. 

 Hungerford, labelled, "P. plectostoma from Sik- 

 kim." At first I was inclined to refer this 

 specimen to Plectopylis hanlcyi, but upon further 

 examination it appears to me to pertain to the 

 species now under consideration ; the measure- 

 ments are the same as in the specimen from 

 Darjeeling. An immature specimen in my collec- 

 tion, with four whorls completed, has the armature 

 near the end of the fourth whorl, and identical 

 with that of a mature shell, except that it is 

 smaller. A specimen in Colonel Beddome's collec- 

 tion, from the Naga Hills, labelled with the 

 manuscript name, Plectopylis mimita, Bedd., I also 

 refer to this species ; it is, however, a little 

 smaller, measuring only 4 millimetres in diameter ; 

 it is also a little more raised in the spire, and is 

 more shining and darker. 



(To be continued.) 



