4 PROF, E, A. MINCHIN ON THE [May 2, 
authors have been in agreement as to the names to be employed 
for the genera or as regards the grouping of the species, especially 
in the more primitive and interesting section of the Calcarea 
Homoceela. 
The characters, for instance, by which Breitfuss defines the 
genus Leucosolenia of Bowerbank (1864) are suchas would exclude 
from it all, or nearly all, the species which I should refer to it, 
including, as I have shown elsewhere, even Bowerbank’s type 
species of the genus, LZ. botryoides ; while Lendenfeld has always 
consistently declined to make any use at all of the oldest generic 
name amongst the Ascons. In short, with the exception, perhaps, 
of the malarial parasites, there is probably no other group in the 
animal kingdom in which the nomenclature is in so confused a 
state as in the Homocela. The species which forms the subject of 
the present memoir illustrates well the statement just made. 
It is a veritable comedy of errors that I have to set forth. 
The name Leucosolenia contorta was given by Bowerbank in 
1866 [1] to certain small sponges from the Channel Islands— 
Guernsey, and the Guliot Caves, Sark. It is not very clear, 
however, what Bowerbank considered the distinctive characters 
of his species, since his diagnosis would apply to almost any Ascon, 
He states that “the form of this sponge is so distinctly different 
from that of Z. botryoides that ....it cannot well be mistaken 
for that species... . Z. contorta always appears to consist of a 
mass of contorted inosculating fistule.” Further, that “the 
external surface of Z. contorta is also sparingly furnished with 
recumbent acerate spicule, mostly disposed in a longitudinal 
direction, and I have never observed like spicule on the surface 
of L. botryoides.” He was a little doubtful if his sponge were not 
really identical with Spongia complicata Montagu (1816), but 
came to the conclusion that Montagu’s figure of complicata was 
“really a very characteristic figure of Spongia botryoides of Hillis 
and Solander,” and that therefore the name complicata was to be 
rejected. Finally, Bowerbank remarks that contorta and coriacea 
might be mistaken for each other in the dried condition, but that 
‘“‘the total absence of defensive spicule on the cloacal cavity of 
L. coriacea” (meaning apparently the gastral rays of the quadri- 
radiates) readily distinguishes it, 
If we put Bowerbank’s description into more modern terms, it 
amounts to this—that Z. contoria was characterised (1) by form 
and appearance (contorted inosculating tubes), (2) by the presence 
of triradiate, quadriradiate, and monaxon spicules. The term 
“equiangular ” applied by him to the triradiate systems need not 
be taken into account, since he applies the same term to the 
sagittal spicules of botryoides. It is not necessary to point out 
that the characters given by Bowerbank are not sufficient to define 
a species of Ascon; and when it is seen that botryoides always 
has monaxon spicules, as [ have shown elsewhere, and that contorta 
may frequently lack them; that the specimen of botryoides from 
which Bowerbank figured spicules (Brit, Spong, 111. pl, iii, figg, 3, 4) 
