MOLLUSCA OF INDIA. 37 
‘‘ Habitat forma typica prope Landour Himalaye occidentalis, 
varietas in valle Rungun prope Darjiling, rarissime.” 
“T got a single fresh specimen of this fragile species in October 
1842, in a precipitous rift at the back of the Seinty or Queinty 
ridge, eastward of my grounds at Rockville, near Landour, and at 
an elevation of nearly 7000 feet. The Messrs. Blanford have lately 
procured the variety, but rarely, and in a dead state, in the Rungun 
valley in Sikkim, at an elevation of 4000 feet. From the data 
furnished by Mr. W. T. Blanford respecting the resort of species at 
Darjiling, I observe that the same forms evince a disposition to 
descend there to a lower altitude above the sea than in the western 
portion of the range—a circumstance attributable probably to the 
greater moisture of the climate,—whereas the drought and hot 
winds, which prevail for so many months in the year at the base of 
the western ranges, drive species to a greater height in order to 
obtain the humidity necessary to their existence. At Landour this 
form escaped the active researches of the late Dr. J. F. Bacon; and 
I am not aware of its having yet occurred to Capt. T. Hutton.” 
Locality of specimen figured. Nag-Tiba range, near Mussoorie, 
N.W. Himalaya. 
Shell globosely trochiform ; sculpture regular, distant longitudinal 
striation (furrows), crossed diagonally by sharply-defined close-set 
strie, below regular and concentric; spire conoid, sides flat ; 
whorls 6, sides moderately convex; aperture ovately lunate; peri- 
stome thin. 
SiraLa Rmmrcoua, var. (Plate IX. figs. 4, 4a, 4b, 4c.) 
Locality. North and west Khasi Hills (G.-<.). 
Shell globosely conical ; umbilicus hidden ; sculpture, moderately 
strong, regular longitudinal striation or furrowing, with diagonal 
coarse ridges of growth; colour very pale horny brown; spire 
conical, sides slightly convex; suture fine; whorls 6, convex, the 
last tumid and rounded; aperture ovately lunate, oblique; peri- 
stome thin, columellar margin strong, reflected, perpendicular. 
Size: major diam. 0°21 inch, alt. axis 0°16 inch. 
a 5:4 mm., ae 4:1 mm. 
Is a very abundant species in the above hills; the apex of the 
shell is much more acute than in examples from Mussoorie, and it 
is also larger. 
SrraLa RIMIcoLA, var., Benson. (Plate IX. figs. 3, 3a.) 
Locality. Darjiling, 4000 feet (W. 7. B.). 
Sculpture, very fine close longitudinal ribbing or furrowing, 
crossed by extremely fine diagonal regular striz of growth, below 
rather coarser concentric ribbing, near umbilicus. 
Size: major diam. 4°5, alt. axis 3:0 mm. 
4 OS yey, 050-12 imeh. 
Has flatter sides to spire and whorls, and is more depressed, with 
finer spire than typical rimicola, 
