170 Dr. J. E. Gray on the Arrangement 
defensive spicules of any form. The fragment was a very 
minute one, and it might be not a good specimen of the 
sponge; but I should like to be assured that Dr. Bowerbank, 
in preparing his slide, has not somehow mixed up the sponge 
of the Japanese and Portuguese species together; and Fa e 
that Professor Bocage will give us a figure of the spicules he 
finds in the Portuguese Sponges. But should it even prove to 
be correct that the Sponges attached to Hyalonema mirabile 
and lusitanicum both belong to the genus Carteria, it would be 
no proof that the coral belongs to the Sponge. Mr. Carter 
has well observed that, if the polype that forms the bark can 
secrete the siliceous spicules that occur in the bark, there can 
be no difficulty in believing that it can secrete the longer 
spicules that form the rope-like axis. 
Even if the Sponge of the two Hyalonemata belongs to the 
same genus, that affords no proof that the glass rope is part of 
the Sponge. It is remarkable that the Palythow, to which the 
polypes of Hyalonema are most nearly allied, are constantly 
parasitic on one particular animal; and yet we do not believe 
that they are part of the animal on which they are parasitic. 
Some forms of Palythoa are only parasitic on some bodies in 
a peculiar state. The one that Dr. Johnston called Spongia 
suberea (see Mag. Nat. Hist. vii. p. 491, f. 60) is only found 
growing on shells; but it is never found growing on a livin 
shell, but only on shells inhabited by Bernhard crabs; adil 
somewhat similar species with the same habit are found on 
the American coast and in other parts of the world ; yet no 
one thinks there is any connexion between the Palythoa and 
the crab or the shell, as Dr. Bowerbank does because the 
Japanese and Portuguese Hyalonemata are sometimes found 
affixed to a Sponge of the same genus. ok ee 
Dr. Bowerbank states that he has found in the Portuguese 
species of Carteria all the spicules that are found in the Japanese 
species, but one. If his observation is accurate, this, to: my 
mind, goes to prove that there are two species of Carteria 
(C. japonica and. C. lusitanica) as well as two species of Hya- 
lonema, each having an Hyalonema sometimes growing from 
them, as the species of Palythoa on different coasts live on 
shells inhabited by Bernhard crabs. _ | 
I find that I neglected to state that the genus Carteria is 
named in honour of Mr. H. J. Carter, of Budleigh-Salterton, 
who observed. so accurately the structure, habit, and develop- 
ment of the Spongilla of Bombay, and has described so well 
the structure and development of the Foraminifera. , 
I may also say that the genus Jngallia is named in honour 
