244 Transactions of the [ Soar, Noe ae teat 
possessing the same generic characters as the one subsequently 
described in the ‘ Philosophical Transactions.’ * 
As a species, my sponge differs from Pheronema Carpenteri in 
many points. In the first place, in the invariably more or less 
globose contour of its body, and in its large and outwardly expand- 
ing oscular orifice. In Pheronema Carpentert the sponge body is 
usually sub-cylindrical, with an entirely cylindrical osculum. An- 
other distinction is evidenced in the origin and distribution of the 
long, silvery, hair-like, anchoring spicula, which, spreading out on 
all sides, serve to fix the sponge in the treacherous ooze from 
which it was taken. In Dr. Wyville Thomson’s species these 
originate in a number of distinct fascicles springing from the lower 
portion of the sponge, while in my own they are distributed equally 
throughout the greater portion of the external surface, without 
having any definite fascicular arrangement. Dr. J. EH. Gray has 
considered this character sufficient for the institution of a new 
genus for its reception; but without committing myself to that 
extent, I regard this feature as an auxiliary and important one in 
proof of its specific individuality. But in addition to the readily 
recognized characters of external contour, there are others afforded 
by the internal spicular structure that assist us in discriminating 
between this form and Pheronema Carpentert. Having examined 
the spicules of both species I have failed to find in the last-men- 
tioned one the long attenuate spinulate forms which are present 
in mine, and also long attenuate erectly-spmed ones, which likewise 
occur in Pheronema Grayi. I may also remark that the shafts 
of the recurvato-birotulate spicula (Amphidisci, W. Th.) are more 
profusely echinate in Pheronema Grayi than in P. Carpenteri. 
This more or less spinous character of the skeletal elements may 
be quoted as being of very great service in the specific diagnosis of 
many other forms; as, for instance, between Aulodictyon fecunda 
and another species of the same genus I shall presently introduce. 
The specimen exhibited this evening, in company with about a 
dozen more examples, was procured with the aid of the fishermen’s 
hooks at a depth of, at least, 600 fathoms. On first being brought 
on board, the sarcode investing and constituting the sponge body 
was of a brilliant orange colour, a hue remarkably predominant 
among the Protozoa, while their long, hair-like, anchoring spicula 
hung about them in matted tresses, cemented together by the 
* Since writing my first paper descriptive of Pheronema Grayi, I have seen 
Dr. Leidy’s representation of his species (‘American Naturalist,’ March, 1870). 
That it is generically identical with the one described by Prof. Wyville Thomson, 
I have no longer any doubt, and must even consider it to be very closely allied 
specifically ; it possesses the same cylindrical outline and the same fascicular 
arrangement of the anchoring spicula. The smooth upper surface of Dr. Leidy’s 
sponge is evidently owing to its having undergone a considerable amount of wear 
and tear before it was deposited in his museum, I possess a specimen of P. Grayi 
similarly denuded. 
