16S LAND AND FRESHWATER 



The admedian teeth have a single cusp on the outer side, the 

 marginals are unevenly bicuspid, and those on the outside become 

 very minute. 



The jaw (fig. 1 b) has a small central projection. 



Macbochlamts SEQuius, n. sp. (Plate CVI. figs. 2-2 y.) 



Locality. Damsang, Daling Hills, W. Bhutan. 



Shell (fig. 2) differs in its characters from that of M. sequax ; it 

 is slightly more solid, globose, with more rounded apex, the major 

 axis of the aperture directed obliquely downward, instead of hori- 

 zontally as in M. sequax. The sculpture of these Damsang shells 

 is rather coarse, somewhat wavy, longitudinal striation. Colour 

 pale umber-brown. The shell of the specimen dissected had 

 4 whorls and was 11 mm. in major diameter, and therefore not 

 fully grown. 



The largest specimen measures : major diam. 12*25, alt. axis 

 5'75 mm. 



Animal in spirits (fig. 2 a) with pale foot, black head and 

 tentacles, and a slightly darker tint near the extremity of the 

 foot. The right shell-lobe (fig. 2 b) is rather short and broad ; 

 the left shell-lobe (fig. 2 c) small ; the left dorsal lobe is in two 

 parts, one on each side of the left shell-lobe (fig. 2 a). 



In the generative organs (fig. 2 d) there is not much difference 

 to be found when they are compared with those of M. sequax 

 (fig. 1 a). The kalk-sac was well developed and shows a spermato- 

 phore within it (fig. 2 e). The teeth of the radula (fig. 2 g) are of 

 the same form, the formula differing slightly : 



-h 20 . 2 . 10 . 1 . 10 . 2 . 20 -h 



The jaw (fig. 2/) has a nearly straight edge with a slight central 

 projection, and differs from sequax from Darjiling (vide fig. 1 b). 



Macrochlamys SEQUIUS, G. A., very young. (Plate CIX. fig. 7.) 



Locality. Darjiling, ex Coll. Calcutta Museum. 



Shell depressedly conoid, umbilicated, glassy, rather solid ; 

 sculpture fine, but distinct and regular longitudinal striae ; colour 

 pale sienna-brown ; spite flatly conoid ; suture shallow ; whorls 

 nearly 4, the last well rounded ; aperture ovately lunate, sub- 

 vertical ; peristome slightly thickened, columellar margin very 

 slightly reflected. 



Size : major diam. 5'0, alt. axis 1"9 mm. 



The very young shells of M. sequius, as well as superflua, W. Blf., 

 were sent to me by G. Nevill many years before the adult shells had 

 been described. To better recognize small forms, I made a good 

 many drawings, as being the only way of seeing how the species 

 varied in this very difficult group of shells. I have found it useful 

 to draw, with the aid of camera lucida, the protoconch and two or 



