474 Records of the Indian Museum. [Von. XI, 
its spicules adhere to and are even incorporated in what we may 
call for this purpose the ‘‘ skin’’ of the aggressor. 
Amorphinopsis excavans has similar habits, but takes the bor- 
rowed spicules into its own internal parts. 
Stoeba plicata var. simplex differs from these species in that it 
possesses independent powers of excavation and only uses the bur- 
rows of Clionidae as the basis of its own operations. It adapts 
and enlarges these burrows and at the same time not merely 
attaches the spicules of its host to its own surface, but takes them 
into its own inner parts and possibly even utilizes them in 
strengthening its own attenuated and delicate terminal processes. 
Coppalias investigatrix—and possibly also C. penetrans-- 
attack in a similar manner, but its parasitic character is more 
marked, in that, having once penetrated into the burrows of a 
Clionid, it is content with them and so far as its external form is 
concerned becomes a mere cast of them. Moreover, it enters the 
burrows at a comparatively early stage of development and ap- 
pears to have only a short-lived and very inconspicuous encrusting 
phase. ’ 
All these sponges may be classed, in greater or less degree, as 
parasites, in that they appropriate the fruit of the labours of 
other species and even possibly make use in some cases of the 
spicules of the sponges they attack. There is no evidence, however, 
that they feed on the bodies of their victims. In the case of the 
three species of Chondrilia and of Rhabderemia prolifera it is pos- 
sible that the attacking species does so, for the Clionid is actually 
overwhelmed and engulfed, not merely thrust before the invader. 
The method of attack is not the same in the case of the Chon- 
drillae as in that of the Rhabderemia. The former give rise to 
peculiar capitate tentacle-like processes when they approach the 
Clionid or any other body with which they may come in contact. 
The heads of these processes, which are armed with spicules, 
spread out over any surface that they happen to touch. If they 
do so on the surface of another sponge they surround it and ab- 
sorb it completely. 
The Rhabderemia, on the other hand, which forms a much thin- 
ner film as a whole, spreads bodily round portions of the Clionid, 
which it ultimately absorbs in a similar manner. 
It is noteworthy that the great majority of all these parasitic 
sponges are known to have free encrusting phases or varieties, 
which are able to exist independently of the labours of other 
species. Coppatias penetrans and C. investigatrix, and possibly 
Rhabderemia prolifera—if the latter is to be regarded as speci- 
fically distinct from R. pusilla—are apparently exceptions. They 
seem to have become specially adapted for a parasitic life, but it 
is very desirable that further investigations should be made into 
their minute structure. 
Most of these sponges are probably able to enlarge the bur- 
rows that they occupy, though there is no evidence that C. inves- 
tigatvix and C. penetrans do so, by the mere expansion of their 
