we 
a 
9a, 
PART VY. 
MOLLUSCA OF INDIA. 205 
EXPLANATION OF PLATE LI. 
Cyclophorus aurora, Bs., d, x 24. Animal from spirit-speci- 
men. Damsang Peak, W. Bhutan Hills. m, the mantle drawn 
back, showing (a.0) the anal orifice and p the penis; 7, the 
rostrum ; f, sole of foot folded together; s.m, shell-muscle ; 0, 
operculum. 
Cyclophorus aurora, Bs., 9, x 2°4. Spirit-specimen. Animal 
withdrawn into the shell. Viewed from the outer side of the 
aperture. Greater portion of shell broken away, showing foot 
folded together. Same locality. 
2a. Ditto: ditto, x 2-4. Viewed from the right side. 
Ditto: ditto, x 1:6. Viewed from the left side, showing form of 
the mantle and the branchial cavity (0.c). 
. Ditto: ditto, x 1:6. Viewed from the right side, to show the 
shell-muscle (s.7). 
. Ditto: ditto, x 16. The mantle cut and opened back, to show 
the anal orifice and interior of the branchial cavity. 
Alyceus nagaensis, G.-A., enlarged, Animal from spirit-speci- 
men. 
—— bierenatus, G.-A. One row of the radula. Much enlarged. 
—— bembex, Bs. Sutural tube (¢) of the whorl of the shell 
broken away, to show the internal orifice of the same (0.t). 
Alyceus nagaensis, G.-A., X 7. The outer right margin of the 
shell broken away, to show the sutural tube (¢)in the internal 
orifice of the same (0.7). 
. Diagrammatic section of the frontal edge of the mantle (m) in 
Alyceus, by which the sutural tube is formed. 
Rhaphaulus blanfordi, Bs., enlarged. Animal removed from 
shell, showing the sutural or branchial tube (¢). 
Ditto, x 7. Shell with margin broken away, to show the internal 
orifice (0.7) of the sutural tube (¢), extending forward to the 
peristome. 
Rhaphaulus blanfordi, Bs., x 20. A portion of the shell near 
suture, to show the internal sutural tube (¢) and the external 
sutural tube (¢'), corresponding to that in fig. 7. 
Diagrammatic section of the same across the front edge of the 
mantle (7), to illustrate the supposed formation of the internal 
and external sutural tubes (¢, 2’). 
