var. spinispiculum, Ctr, 155 
etliata and SS. coronata on the one hand and S. raphanus on 
the other, which may, if constant, claim specific distinction 
for the latter; I allude to the prismatic form of the radial 
chambers in S. raphanus, whose transverse section made lon- 
gitudinally to the body, midway between the surface of the 
cloaca and the conuli, presents a hexagonal arrangement with 
triangular spaces between the hexagons, first noticed by 
Hickel in his synoptical table of these sponges (op. e7t. vol. il. 
p- 294), while in Sycandra ciliata and 8S. coronata a similar 
section shows the chambers to be c¢rcular or cylindrical. How 
far this is sufficiently persistent to justify specific separation 
I am not prepared to state. 
Carefully comparing Hiickel’s description of Sycandra ra- 
phanus with the species that prevails here, which in all re- 
spects agrees with that from the north of Shetland which I 
have named “Grantia ciliata, var. spinispiculum ” (“ Sponges 
dredged on board H.M.S. ‘ Porcupine,’”’ ‘ Annals,’ 1876, 
vol. xviii. p. 468, pl. xii. figs. 6 and 7), I can see no differ- 
ence between the two except in the presence of the spiniferous 
spicules in the latter, to which I shall presently allude, but 
which Hiickel does not notice at a// either in his descriptions 
or illustrations, although F. E. Schulze a few years later 
illustrated and described them particularly in Sycandra ra- 
phanus (Zeitschrift f. wiss. Zoologie, 1875, Bd. xxv. 3es 
Suppl. pp. 254 and 255, Taf. xix. fig. 1, a-d). 
Now the fact of such spinous spicules having been found in 
Sycandra raphanus compared with their presence here in 
Grantia spinispiculum, whose structure otherwise corre- 
sponds exactly with Hiickel’s description of the former, 
leads me to infer that Grantia spinispiculum and Sycandra 
raphanus are the same, while the prismatic form of their 
radial chambers (and, perhaps, the spiniferous spicules) alone 
distinguishes them from Sycandru ciliata and S. coronata. 
It is the identity or not of the two former which I wish to be 
confirmed, as | de not possess a type specimen of Sycandra 
raphanus from the Adriatic for comparison ; and therefore shall 
give hereafter an illustrated description of Grantia ciliata, var. 
spinispiculum, in all its principal detail, not only for this pur- 
pose, but to illustrate the variety itself, which hitherto has not 
been done. 
In alluding to the acerate spicules which form the outer 
layer of the “collar-ring ” noticed by Lieberkiihn in “Grantia 
ciliata sive Sycon ciliatum” (Archiv f. Anat. u. Physiologie, 
July 1859, Heft iii. p. 373), and subsequently by Bower- 
bank (Trans. Microscop. Soc. J. c. p. 82), Hiickel observes 
(op. cit. vol. ii. p. 308) that they are not to be ny Grantia 
