184 TRICHODINA. 



spiral lines set with short, straight hairs. Specimens in 

 drying etc. very readily lose the hairs and cuticular spiral 

 riblets. 



2. T. MASSONIANA (Crosse). PI. 56, figs. 13, 14, 15. 



Shell imperforate, long-turrite, moderately thick, rather 

 solid; longitudinally, slightly obliquely wrinkle-striate, dirty 

 white under a nearly lusterless somewhat deciduous chestnut- 

 brown epidermis. Spire long, the apex rounded, obtuse; 

 suture impressed. Whorls 8, a little convex, flattened, the 

 embryonic l 1 /^ nearly smooth, without epidermis and of a 

 dirty white ; last whorl very much shorter than the rest of the 

 spire, very obtusely, almost imperceptibly subangular in the 

 middle, tapering downwards. Aperture oval-piriform, dirty 

 white inside. Peristome simple, the margins united in adult 

 individuals by a brownish callous deposit in the form of a 

 projecting cord, which extends along the outer margin of the 

 columella. The latter is quite projecting, arcuate, and trun- 

 cate just short of the base. The basal and outer margins are 

 thin and almost acute. Length 36.5, diam. 13 mm. ; aperture 

 11 mm. long, 7 wide (Crosse}. 



San Thome (Masson). 



Homorus massonianus CROSSE, Journ. de Couchyl., xxxvi, 

 1888, p. 22. Acliatina (Homorus) massoniana CROSSE, t. c., 

 pi. 1, f. 3. H. massonianus KOBELTV, Conchyl. Cab., p. 99, 

 pi. 27, f. 2, 3 (copy from Crosse). 



While very closely related to T. barbigcra, this species dif- 

 fers by the wider, subangular last whorl and the raised, cord- 

 like and usually crenulate or beaded parietal callous. It may 

 however be merely a wide variety of that species. Traces of 

 about 6 spiral ridges are visible in well-preserved specimens, 

 and there is little doubt that fresh shells have cuticular 

 fringes. The peculiar sculpture of waved striae is shown in 

 fig. 15. A specimen measures 37 mm. long, 13.6 wide. 



3. T. CLAVUS (Pfeiffer). PI. 56, figs. 9, 10, 11. 



Shell oblong-turrited, rather solid, obliquely closely striate ; 

 tawny, the base darker; spire turrited, the apex acute. 



