PROCEEDINGS OF SOCIETIES. 129 
deposition of moisture does, however, frequently occur upon 
their surfaces whilst shells are undergoing examination, in 
which case it would be a safe precaution to allow them for 
awhile to remain exposed to the air before returning the 
drawer to the cabinet.” 
September 25th, 1858. 
On the Anatomy of the Spinning Organs of the Araneide. 
By Mr. R. H. Means: 
Tue tegumentary covering of the abdomen in true spiders 
consists of three layers, viz.: Ist, an external, horny, trans- 
parent membrane, more or less densely clothed with hairs ; 
2d, an intermediate soft stratum of pigmentary matter; and 
3d, an expanded network of muscular fibres, which will 
enable the spider to compress the contents of the cavity. 
The spinnarets, seated near the apex of the abdomen, at the 
under side, are mostly six in number, placed in three pairs— 
an anterior, a posterior, and an intermediate pair. The pos- 
terior pair is often prolonged and tri-articulate, when the 
spinners composing it have been called anal palpi. There is 
a fourth pair of spimnarets in Mr. Blackwall’s family of the 
“ Cinifloride,”’ situate in front of the ordinary anterior pair. 
They are short, compressed, and imarticulate. The spin- 
narets are connected with the surrounding integument by 
means of diverging bands of muscular fibres, which enable 
them to move in various directions. In the interior of the 
abdomen, nearer the base than the apex, there is a point 
(opposite the orifice of the oviduct in the female), from 
which several muscular bands radiate im various direc- 
tions, keepmg the different abdominal organs in their 
places. Some are inserted into the integument on both the 
dorsal and ventral surfaces of the abdomen; others run 
backwards in straight parallel bundles, and pass into the in- 
terior of the spinnarets. These last bundles have their fibres 
strongly striated, like the strong muscles connecting the legs 
with the cephalo-thorax. The other muscles mentioned are 
only faintly marked. The interstices between the organs 
in the abdomen are filled with adipose matter, connected 
into lobules by fine cellular tissue. This serves as a reservoir 
of nutriment, and enables spiders to bear very long absti- 
nence. The glandular organs, which secrete the silk, con- 
sist of a number of sacsor bags and convoluted or branched 
tubes, of various sizes and shapes—cach furnished with a dis- 
tinct exeretory duct, which terminates separately on the sur- 
