Mr. H. J. Carter on Tethea muricata. 175 



larger, affords by far the best typical form and detail (for 

 scores of them of all sizes came under my view while descri- 

 bing the sponges dredged up on board H.M.S. ' Porcupine '). 



Schmidt notices a specimen " with the plates " sent to him 

 by Sir Wyville Thomson in May 1870 (Atlantisch. Spongienf. 

 p. 68) ; and seeing that it was closely allied to his StellettUj 

 it was added to the list of his " Anchorinidas " {ib. p. 80), 

 under the name of ^^ Stelletta'''' [Tisijyhonia) agariciformisj 

 the latter, viz. Tisiphonia agariciformis^ being Sir Wyville 

 Thomson's appellation. 



It is strange that Schmidt in 1877 (Archiv f. mikroskop. 

 Anat. Bd. xiv. p. 260) should even " provisionally " call 

 another specimen of this sponge " Stelletta eclmioides,'' which 

 he obtained from the Bay of Naples. 



However, we now know that " Tethea muricaUi^ Bower- 

 bank," has the priority of all these names, while it does 

 not detract from the merit of Dr. Wallich, who dredged up 

 the little specimen described by Dr. Wright, on board H. M.S. 

 ' Bulldog,' as far back as 1860. 



Tethea cranium^ Johnston, has been made the type of my 

 Tethyina, the 16t]i group of the order Holorhaphidota, in the 

 3rd family, viz. Pachytragida (" Notes Introductory to the 

 Study and Classification of the Spongida," '■ Annals,' 1875, 

 vol. xvi.) ; so Tethea muricata^ according to its generic desig- 

 nation, would come in here, where, at p. 198, a list of all the 

 known species is given, with the exception of Tethea antarctica, 

 dredged up by Sir J. Ross in 300 fms., 77^° S. (' Annals,' 

 1872, vol. ix. p. 412, pi. xx.), and T. zetlandica [tb. p. 417, 

 pi. xxii. fig. 2), the former of which differs from all the rest 

 in having no bihamate flesh-spicule (as confirmed by another 

 specimen from the neighbourhood of Kerguelen Island) ; and 

 the latter, viz. T. zetlandica, J now find to differ hardly in 

 more than varietal characters. 



But l^ethea muricata, = 8telletta agariciformis (I. c), cer- 

 tainly, as Schmidt has intimated, agrees more with his 

 Stelletta than with any other known sponge. In the length 

 of its anchoring-spicules, however, it is more like Tetilla 

 polyura, Sdt. (Atlantisch. Spongienf. Taf. vi. fig. 8), and 

 Tethya dactylo{dea,Q. ('Annals,' 1872, vol. ix, pi. x. fig. 1), 

 which causes it in this respect to approach the bearded 

 Hexactinellidas, whose anchoring-spicules again seem to have 

 their length influenced by their usual habitat on the subtle 

 mud of the deep-sea bottom, as the fragment of Euplectella 

 aspergilhim, which was dredged up on board H.M.S. ' Por- 

 cupine,' had no anchoring-spicules at all, its base being 

 directly attached to a branch of Lo'phohelia yrolifera (' Annals,' 



