88 
ORGANIC DEPENDENCE AND DISEASE 
menclatorial procedure. The Vioa prisca and its type being 
undoubtedly worm borings must take a more appropriate 
designation. 
We are referring to Clionolithes, the form C. radicans, 
which enters brachiopod shells by a simple perforation 
and once within the shell substance produces a radiate and 
arborescent or root-shaped colony. Shells are often quite 
riddled by these colonies, which may maintain individual 
independence, no matter how numerous, though at times in 
a thick shell, galleries may so overlie one another as to ap- 
pear massed or felted. It is this form of sponge which may 
be taken as the type of the genus. 
Clionolithes palmatus, which has been found only in the 
soft shales of the Portage group (Upper Devonian), pre- 
sents a somewhat different aspect from C. radicans in its 
broad, sparsely branched or palmate tunnels. 
Clionolithes reptans is a filamentous and vagrant tube 
tunneling just beneath the surface of the host-shell. It is 
common in brachiopod shells of the Lower Devonian and it 
is assigned to the sponges because there seems no better 
present interpretation of it. 
Of entirely different type and of much greater size is a 
perforating sponge which we observe in the Middle De- 
vonian Stromatoporas of Iowa. In this there is a large 
spherical central body from which stout cylindrical arms 
radiate into the coral substance. The formation of the 
tunneling appears to begin with the gradual burial of the 
round centrum with its branches and the subsequent exca- 
vation of additional tunnels by later outgrowths of the 
colony. These sponges have been found both as depres- 
sions at the surface of the coral and as completely buried 
bodies within the coral substance and revealed only by cut- 
ting. 
This parasitic sponge we shall designate Topsentia de- 
vonica. 
Worms. The boring worms of the existing fauna have 
