284 Mr. H. J. Carter on hnown Fossil Sponges. 



Salterton, Devon) ; but beyond this nothing identifiable with 

 the sponge-structure of this family. 



Nor have I ever found any remains of the (equally corneous) 

 ECHINONEMATA, in which the echinated fibre, if ^ well 

 preserved, could hardly pass unrecognized. That of Dirrho- 

 jjalum [Phcamia), to which Dr. Hinde has alluded in his 

 Monactinellidai (Cat. Foss. Spong. Brit. Mus. p. 20), and 

 which I had placed in my order Echinonemata, requires 

 further investigation, as Dr. Hinde himself has intimated, 

 before this can be confirmed. 



But when we come to my HOLORHAPHIDOTA (Order VI.) 

 we do see that accumulations of Monaxonid spicules have 

 been found heaped together as well as in separate spicules — 

 e. g. Puhillus TJwmsoni^ Crtr., from the Carboniferous of 

 Dumfries in Scotland (' Annals,' 1878, vol. i. p. 137, pi. x. 

 iigs. 1-6), also Ehai)Mdhistia vermiculata, Crtr., from the 

 Carboniferous of Ayrsiiire {ih. ih. p. 140), which has been 

 described by Dr. Hinde under the name of ^^HapUston vermicu- 

 latum'' (Palffiont. Society's Publ. vol. for 1887,_^. c), Clima- 

 cospongia radiata, Hinde (Cat. Foss. Spong. Brit. Mus. p. 18, 

 pi. i. figs. 1, 1 «), Lasiocladia compressa {ih. p. 19, pi. i. fig. 2), 

 and Acanthorhaphis intertextus {ib. p. 20, pi. i. figs. 3, 3 a) ; 

 to which may be added Zittel's two species of his Scolio- 

 rhapMs from the Upper Cretaceous of North Germany (Foss. 

 Sponges, Abhandl. der k. bayer. Akad. d. Wiss. ii. C. xiii. 

 Bd. ii. pp. 94, 95, Taf. xii. figs. 1 a, h, and 2). 



The layer of pin-like spicules discovered by Dr. Harvey B. 

 Holl on the surface of the Calcisponge Verticillites helvetica, 

 deL. ('Annals,' 1884, vol. xiv. p. 27, pi. i. figs. 6-10), 

 appears to me to have consisted of those of a parasitic species 

 of Suberite, of which there are many existing instances on other 

 sponges. The boring sponge, Cliona, whose existing species 

 are chiefly characterized by a pin-like spicule, has also been 

 recognized in several cases more by the peculiar form of its 

 excavations in fossilized casts than by that of the spicule, which 

 has not been described if ever seen. 



We next come to the third and fourth families of my HoLO- 

 RHAPHlDOTA, viz. the Pacliytragida and Pachastrellida, now 

 called " Tetractinellida," of which the only entire specimen 

 among the three groups of the former that has been described is 

 that of a SteUetta,\iz. S. inclusa, Hinde,which, as it occurs in the 

 interior of a fiiut, is easily recognized by being w/iaccompanied 

 by the coating of siliceous spheroids which chiefly separates that 

 genus from Geodia (Cat. Foss. Spong. Brit. Mus. p. 24, pi. i. 

 figs. 6, 6 a) ; while in the first division of the latter, viz. the 

 Pachastrelliua (group 17), four specimens have been described, 



