CLAUSILTA. 331 



bears some resemblance to C. orientalis, Mab. but is less inflated 

 about the middle. I have only seen two specimens which are 

 in the British Museum. One of these is the type figured in 

 Conch. Ind., measuring 33-5 x 5-75 mm., presented by Mr. Harvey 

 who acquired the Hanley collection by purchase. Hanley's figure 

 is enlarged (41 mm. length), although there is no indication of 

 this fact on the plate. The other shell (here figured with 

 its detached clausilium and the palatal plicae) is in the Theobald 

 collection and is composed of 12| whorls, measuring 32 x 5'75 mm. 

 The latter is a very fine specimen, possessing a peristome with 

 more expanded margins. 



292. Clausilia masoni, Theobald. 



Clausilia masoni, Theobald, J. A. S. B. xxxiii, part 2, 1864, p. 246 ; 



Hanley & Theobald, Conch. Ind. 1870, pi. 24, fig. 8 ; Sowerby, 



Conch. Icon, xx, Clausilia, 1875, pi. 8, fig. 69 ; Pfeiffer, Mon. 



Helic. Viv. viii, 1877, p. 540. 

 Clausilia (? Nenia) masoni, Blanford, J. A. S. B. xli, 1872, p. 206, 



pi. 9, fig. 18. 



Clausilia (Phaedusa) masoni, Nevill, Hand List, i, 1878, p. 184. 

 Clausilia (Phaedusa (Hemiphaedusa)} masoni, Pfeiffer & Clessin, 



Nomencl. Helic. Viv. 1881, p. 394. 

 Clausilia (Gamier ia) masoni, Mb'llendorff, Jahrb. Deuts. Malak. 



Ges. xiii, 1886, p. 207 ; ibid., Nachr. Dents. Malak. Ges. xxx, 



1898, p. 77. 



Original description : " Testa arcuato-rimata, f usiformi, tenui, 

 costulato-striata, pallide castanea. Apice intacto. Sutura ex- 

 cavata. Anfractibus decem, sub-planatis, ultimo angustiore, supra 

 aperturam fortiter striato, juxtaque suturam fossa, laminae interi- 

 oris cursuin monstrante, notata. Lunella distincta ; interdum 

 non. Lamellis quiuque, duabus parietalibus tenuibus, distinctis, 

 intus conniventibus ; reliquorum binis fortibus ad aperturam 

 divergentibus ; tertia post lunellam valde tenui, inconspicua. 

 Apertura rotundato-auriformi-soluta. Peristomate expanse, 

 renexiusculo. 



"Longit. 21 ad. 29 mm. lat. 4 ad. 5 mm." (Theobald.} 



Hab. Burma : Tonghu (Theobald}. 



In the present species three folds are visible on the upper 

 or parietal margin of the peristome, for in addition to the two 

 parietal folds, present in most species, the subcolumellar fold here 

 also reaches the inside margin, while the upper palatal plica runs 

 close to the peristome. Of the two parietal folds the upper 

 terminates at the outer edge of the peristome, but the lower does 

 not reach quite so far. The clausilium is likewise visible for the 

 greater portion of its length upon looking into the aperture. 

 Clausilia masoni is characterized by the rather distant, fine, 

 plicate-striate ribs, which are especially prominent on the latter 

 half of the last whorl. 



