18 PROF. E. A. MINCHIN ON THE [May 2, 
Clathrina spinosa Minchin, ibid. 
Leucosolenia spinosa Breitfuss, 1898, Arch. f. Naturges. lxiu. 1, 
pels. 
(The following references, on the other hand, probably do not 
relate to the true contorta.) 
Ascandra contorta Barrois, 1876, Ann. Sci. Nat. (6) 11. Article 
11, p. 35, probably refers to Leuwcosolenia complicata. 
Leucosolenia contorta Carter, 1880, Midland Naturalist, 11. 
p- 195. The author remarks that ‘ Bowerbank’s illustration of 
the linear spicule is defective. There are two forms, quite different 
from each other and from Dr. Bowerbank’s figure.” I consider 
it probable from this statement that Carter was dealing with a 
specimen of Leucosolenia complicata. 
Ascandra contorta Breitfuss, 1898, Arch. f. Naturges, lx. 1, 
. 214, refers to a specimen of Leucosolenia complicata ; so pro- 
bably also the sponge described and figured by the same author in 
Mém. Ac. St. Pétersbourg, 1898 (vili.) vi. p. 15, pl. i. fig. 1, and 
cited by him in other memoirs. 
And finally it should be mentioned that the numerous specimens 
sent out from Sinel and Hornell’s Zoological Station, Jersey, are 
all, so far as I have seen, specimens of Lewcosolenia complicata. 
Diagnosis.—Trivadiate systems equiangular, with or without 
gastral rays; the quadriradiates generally more numerous than 
the simple triradiates. Rays of the triradiate systems tapering 
imperceptibly for the proximal half or two-thirds, then narrowing 
more rapidly to a sharp or moderately blunt point. Gastral rays 
sometimes short, more usually longer than the basal rays, very 
slender, sharp, and straight or irregularly curved. 
Monaxons at least twice as thick as the basal rays of the tri- 
radiate systems,—varying in different specimens from a moderate 
size to gigantic proportions, spindle-shaped, usually slightly curved, 
and usually with a distinct constriction near the middle of their 
length ; sometimes very few in number, sometimes absent 
altogether. 
The chief objection that can be made, it seems to me, with 
regard to my treatment of the species, relates to the position of 
spinosa. Naturalists concerned chiefly with the arrangement 
of specimens in bottles'on shelves will perhaps object to my 
“lumping” together two forms which can be separated by a definite 
character, although by one only. Those who reason thus will, no 
doubt, prefer to retain spinosa as a “species” distinct from 
contorta ; in that case the type of Bowerbank’s contorta belongs 
to the former species, a fact which raises alarming problems of 
nomenclature. The range of variation seen in contorta has its 
natural and logical termination in the form spinosa, and justifies, 
in my opinion, placing the latter asa synonym. Moreover it is 
often extremely difficult to be certain that monaxons are really 
absent in a specimen of “ spinosa.” They may be so scarce that 
they have been simply overlooked. 
After arriving at the above conclusions with regard to the 
