ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
interest, as tlie only previous zoological visitor to the island was a Dutch 
collector of birds. Nearly all the butterflies were found to be allied to 
or identical with those collected by Mr. H. 0. Forbes in Timor-Laut, but 
among them was the wandering Anoxia plexippus, found many thousands 
of miles from its original American home. The land and freshwater 
shells seem to be more similar to those of Timor-Laut than of Timor, 
between which Darama lies. 
Mollusca. 
a. Cephalopoda. 
Shells of Sepia, Spirula, and Nautilus. * — Dr. A. Appelldf, after 
describing in detail the shells of these Cephalopods, institutes a com- 
parison between them. In all three the chief divisions can be 
distinguished ; an outer shell-wall and an inner chambered part ; the 
former is structurally composed of distinct portions between which there 
are boundary lines which are always distinct and often sharply marked. 
The inner chambered part consists in all three of spaces bounded 
by the shell-wall and by septa. The septa are composed of layers, and 
these layers are direct continuations of those of the shell-wall. 
In Spirula and Nautilus the siphon is well developed, but rudimentary 
in Sepia ; in the two former it consists of two divisions, a tubular 
continuation of the septum, and of the same structure as it, and of 
another continuation which has a softer structure. In Sepia it is 
chiefly the upper or dorsal parts of the septa and of the siphon that are 
developed, and this is in relation with the flattened form of the shell ; 
the homologies with the other two shells seem, however, to be clear. 
The cavity which is regarded as the rudimentary siphon-cavity seems 
to owe its form to the fact that if the shell became more and more 
flattened, and at the same time increased in breadth, it must, unless it 
is to occupy too much room, be diminished in height ; this is effected 
by the lower parts of the septa and siphon being more and more com- 
pressed, until, as in Sepia , they are brought together in the hinder part 
of the shell; an intermediate stage is to be seen in the eocene 
Belosepia. 
Spirula and Nautilus have a fleshy siphon which is a tubular pro- 
longation of the mantle and is enclosed in the shell-siphon ; a 
corresponding structure has been found in Sepia , where a pointed 
(though not hollow) projection of the hinder part of the mantle is 
continued into the rudimentary siphon-cavity. The chambers of Spirula 
and Nautilus agree in being, for the most part, hollow, and have shafts 
in a small part only ; there are, however, shafts through the whole 
extent of the Nepzct-shell ; their presence is to be sought for in the 
feeble structure of the septa, for they serve as supports. The chambers 
are in all three forms secondary structures, for the cavities are at first 
filled with a soft chitinous mass, which splits later on, and becomes 
pressed against the walls of the chambers, 
The shell-muscles are completely homologous in Sepia and Nautilus , 
but, in the present state of our knowledge, it is impossible to say how 
far this is true of Spirula. Although the three shells in their chief 
characters agree with one another, it is not to be denied that they exhibit 
* Iv. Svenska Yet. Akad. Hdlgr., xxv. No. 7 (1893) 106 pp. and 12 pis. 
