6 
cesses a3 superimposed flaps, each in shape of a child’s hand*. This 
i ep etn me om appanage A Pel 
fe eee 
exactly the same in different specimens, nor even in same 
men at both sides. Pacdatiplion ef Rasveltes acantonaae 
tacles to the external labial processes, but does not mention their 
number in the internal processes. Prof. Owen found twelve tentacles, 
Prof. Valenciennes thirteen im each of those four processes. In the 
external processes Prof. W. ss observed twelve tentacles on each 
side, as was observed also The internal seem to 
have in general a somewhat eames Prof. Vrolik observed in 
this layer fourteen on each side ; I found also fourteen at the left and 
sixteen at the right side. The external labial processes are united in 
the mesial line at the ventral side above the funnel by a membrane 
with numerous fine folds on the inside; the internal approach here 
nearer to each other and are united in a similar manner ; the commis- 
sure presents on the inside, towards the dorsal surface, seventeen OF 
eighteen eminent, compressed, longitudinal folds, like the parallel 
ridges in the olfactory cavity of Fishes. This part is, according to 
Prof. Owen’s opinion, the organ of smell ; hast: A. lalione, teatisdeele 
folds are only rudimental digitations completing the circle of the in- 
ternal labial processes, and tinsilar to the more numerous and smalles 
folds of the external circle, or even to the fringed margin of the lip 
round the mandibles. 
In respect to the observation of Valenciennes concerning the man- 
dibles, it is perhaps not unnecessary to note that I saw them in differ- 
ent specimens always covered with a calcareous white matter, as has 
Secesalacrrid-in:iles Aeelcndenam> dteaiation of: tietaaiaealiaa a 
eminent friend Prof. Owen. 
The sexual difference of the Nautilus requires still farther elucida- 
tion. Prof. Owen’s description was relative to a female, and also all 
the other specimens observed by subsequent authors, or preserved 
hitherto in the museums, seem to be of female specimens. Hence it 
seems to follow that males are rarer; a similar circumstance of un- 
equal number has been noted in many other animnas of several classes. 
recent observations of Kélliker and some other authors havi 
elucidated the true nature of that abnormal animal form, not — 
ce i yarn nga sa found in the shell of the (al 
) Aryonauta, and formerly described as a genus of base un 
the name of Hectocotyle by Cuvier, would lead us to 
males of the Nautilus living like parasites with the teal endl 
There exists however not the least indication in the different memoirs 
of Owen, Valenciennes and Vrolik, that such parasites were present. 
I can say that in Nautilus the sexual difference is not so great, and 
that the male lives in a shell like the female. I was fortunate enough 
to observe one specimen of a male, which was kindly presented to me 
po Sots rst ~ hebmvimgh Seat rtioed et oe 
the Professor of Botany, W. H. de Vriese. The differences it showed 
* “ Zijnde ieder lap gefatzoeneerd als een hand van een kind.” (Amboinsche 
Rariteitkamer, p. 60.) 
