382 A. A. Julien on Sponge-Spicules, 
a dozen specimens have been observed, all of which were frag- 
ments like that sketched in fig.4. These fragmentary spicules 
differ from those of A in their minute size and in being marked 
ogy (stated below) in regard to the number of the spines upon 
the nodes, I have ventured in fig. 4 to reproduce in lighter lines 
the lost portion of the spicule. 
Sy LCT ee a SO aes pe = 
Magnified 436 diameters, 
The surfaces between the nodes are more or less concave, and 
the intervals, though nearly equal in the same spicule, vary from 
the gz's5 to the 5,55 of an inch, averaging the 5,3: ut this 
variation seems to be partly occasioned by the contraction of 
the intervals between a few of the central nodes, and in the 
larger specimens the length of the intervals (as well as the dis- 
tance of the extreme node from the end of the spicule,) is quite 
regularly ihe s255 of an inch. 
In the smaller spicules the nodes are crowded nearer together 
are apparenily composed of minute rounded projections, an 
ble rings or raised fillets; but in the larger the spines are 
distinct. 
n a progression 
which varies in different specimens. In the largest spicule found 
oe extremity of the perfect spicule to the other, supply Ne a 
6 
3 eet LS 
“ “ a =: 46 
4 
iene 3 
fcs% 
