236 Records of the Indian Museum. (Vor. Ils 
ful iridescent patch on the dorsal surface at the posterior end of 
the body. The pore, situated at the ventral posterior end of the 
body in the present genus, leads into a gland the function of 
which has never been made clear. This gland is covered by a 
muscular coat under and amongst which lies (in the present 
specimens) a thin iridescent layer which does not extend to the 
many-furrowed inner wall, and only traces of iridescence were 
observed outside the lower surface of the gland Besides the 
above-mentioned female, two others (M °°’ *°), showing no ex- 
ternal iridescence, displayed, when the skin was removed, flashes 
of golden-green and pink. In one of these females the gland was 
pale purple and the pore had a purple tinge, but on being opened 
no trace of purple fluid could be seen. Wiilker, op. cit.. p. 32, 
has remarked on the existence of a purple gland in this part of 
the body in Sefiella, discovered by Appellof. He alludes also 
to the striking coloured appearance figured by d’Orbigny and 
Férussac for S. ornata (Rang) at the dorsal posterior end of the 
body, and suggests that if a living example could be examined a 
luminous organ might be found in this situation. The adornment 
figured by d’Orbigny is, however, probably similar to the irt- 
descent patch described above, which would seem, moreover, 
to be evanescent in alcohol, no specimens exhibiting it excepting 
those which had been preserved for less than a year when 
examined. Steenstrup has remarked with regard to the shell in 
Sepia that the proportion which the last loculus bears to the area 
of the shell varies according to the season of the year. Jatta 
says with regard to this ‘‘ while the sepium increases in volume 
““and therefore augments the number of lamelli, the striated area 
‘* becomes larger while the smooth area diminishes: as a conse- 
““quence of which in the same species there may be found 
‘“* according to the stage of growth of the bone, and the greater 
‘“or less activity in the formation of lamelli, and, therefore, 
‘* perhaps also according to the seasons, the two areas now equal 
““and now one prevailing above another.’’ ‘The shells of sixteen 
males and twenty females from the present collection were 
examined. The limited amount of evidence thus available seems 
to show that the limbs of the inner cone become accentuated with 
age and are then widest in the female, and, also, that individual 
variation exists as to their thickness and height. It will be ob- 
served in the specimens figured (pl. xxiv, figs.1-8) that the striated 
area comprises more than half of the length of the shell in youth- 
ful specimens, and that the shell of a very young female is not 
broader in proportion to its length than that of a male. The 
shells of older specimens usually have the last loculus occupying 
about two-thirds of the length of the shell. The curvature of the 
parallel lines formed by the margin of the striated area varies 
occasionaliy, as is seen in the shell of the largest male figured, 
the other specimens exhibiting what appears to be the usual form. 
The dorsal surface is coarsely granulated and the shell beneath it 
is striated longitudinally. This can be seen in young specimens 
