352 
Mr. H. J. Carter’s Contributions 
Dr. Bowerbank (Mon. Brit. Spong. vol. i. p. 234, pi. ii. figs. 41, 
42), who merely states that the sponge producing it was 
found lining the tortuous tube of an Annelid in soft limestone 
(? Millepora alcicornis), like Hymeniacidon celata , Bk. (1866), 
= Cliona celata , Grant (1826), and Vioa , Nardo (1839); it 
should be remembered that Dr. Bowerbank considered the 
excavations of Cliona to have been formed by an Annelid 
(Mon. Brit. Sp. vol. ii. p. 220),— after which Dr. Gray pro¬ 
posed the generic name 11 Samus ” for the kind of sponges 
producing this spicule, and S. anonyma for the species (Proc. 
Zook Soc. 1867, p. 526). My dear old friend was wrong, how¬ 
ever, in allying it to Axos Cliftoni or to any of Duchassaing’s 
species of Vioa, if the inference of the nature of Samus above 
given be correct. 
• This brings us to the question whether Hancock, in his 
first excellent paper on the Excavating-powers of Cliona 
&c. (‘ Annals,’ 1849, vol. iii. p. 321), has not based his 
genus u Thoosa' n (ib. p. 345) upon spicules belonging to a 
Samus, seeing that those represented by him (ib. pi. xii. 
figs. 10, b, and 11, a, b) are essentially like the spicules of 
Dercitus and Samus respectively, while there is a total ab¬ 
sence of the pin-like spicule, which appears to me to be 
invariably the form of the skeleton-spicule of the Clionidge. 
Further corroboration of this view seems to be derived from 
the fact that, in the mountings of the minute detritus of the 
root-bunch of Euplectella cucumer from the Seychelles, which 
present an innumerable variety of sponge-spicules, the large 
ones of Samus anonyma are present, together with a still 
more complicated and beautiful form, and a flesh-spicule 
(PI. XXIX. fig. 21) almost identical with that which is 
figured by Hancock as characteristic of both species of his 
genus u Thoosa ” (pi. xii. fig. 10, a, and pi. xiii. fig. 2, b ) ; 
while of the spicule referred to Thoosa cactodes , to which I have 
before alluded (viz. pi. xii. figs. 11 a and 11 b), Hancock 
has stated (p. 347) that he was not able to determine whether 
or not it belonged to the species, although he felt inclined to 
the affirmative. 
It might be urged against my view that the representation 
of Thoosa cactodes (pi. xiii. fig. 1) is evidently that of a 
Cliona. But then, as Samus anonyma fills the cavities of 
Cliona , it, of course, would present the same shape ; while 
the absence of the pin-like spicule here, and the presence of 
Samus together with Cliona mucronata in the instances that 
have been mentioned, show that both may be in the same 
excavation, and, from the inference that the excavation was 
made by the latter, that Samus is not a Cliona. 
