432 Prof. W. J. Sollas on the 



We now retuvn to T/ienea micricata, of which at last, in 

 1872, Bowerbank (x.) published a full and illustrated descrip- 

 tion ; and so closely in general appearance and in the size and 

 form of its spicules was it found to resemble Thenea WallicMi, 

 that Bowerbank declared his conviction that they were one 

 and the same species. His manner of viewing- the relations 

 of the two specimens, Kent's and his own, is, however, in the 

 light of further knowledge, somewhat amusing, since he con- 

 siders Kent's specimen mutilated, the upper portion having, 

 he says, evidently been torn away from the base, causing 

 the part described to assume a form very much like that of 

 an agaric ; and he adds that the filiform anchoring appen- 

 dages have very much the appearance of being some of the 

 skeleton-fasciculi of the sponge drawn out of the basal portion 

 at the time of its mutilation. Kent (xi.), in a " Note on 

 Tetliea muricata, Bk., and Dorvillia agariciformis^ Kent," 

 argues against the identification of the two species, resting his 

 case on (1) the agaric form oi Dorvillia {Tli.) Wallichu, (2) 

 its possession of fascicles of anchoring-spicules, and (3) of 

 quadriradiate flesh-spicules (more correctly pauciradiate stel- 

 lates). With reference to the first two distinctive characters, 

 I may confess that I do not place great reliance on them : T. 

 muricata is not unlike T. Wallichu in general form ,* and the 

 agaric form of the latter is not constant. Some of J\Ir. Nor- 

 man's specimens which possess anclioring fascicles and all the 

 spicules proper to the species show no trace of the agaric 

 form ; again, the anchoring fascicles, though usual, are not 

 constant. Other of Mr. Norman's specimens with the agaric 

 form and the proper spicular com])lement of T. Wallichii are 

 entirely devoid of anchoring filaments or of any sign of them. 

 The third character cited by Kent is more important : the 

 curious quadriradiate stellates (to be hereafter described) are 

 abundant and characteristic in T. Wallichii] and since 

 Bowerbank did not meet Kent's objection by replying that 

 they also occurred in his specimen, we may conclude that they 

 were not present ; and hence so far we must admit the specific 

 distinction of Thenea muricata and T. Wallichii. 



In 1873 we again meet with Tisiphonia^ a passing mention 

 being made of Tisiphonia agariciformis^ Kent, by Sir Wyville 

 Thomson (xii.) in the '■ Depths of the Sea.' The suborder 

 " Leptophloea " appears to have* slipped the memory of its 

 author, as he speaks of the species he liad given in its illus- 

 tration as " that pretty little hemispherical corticate form." 

 An excellent illustration of the general form of the species 

 accompanies this notice. 



In 1878 Carter (xiil.) published a ''■ Note on Tethea muri- 



