462 Mr. II. J. Carter on the 



and the same species. Should this turn out to be the case, 

 which name is to be suppressed ? 



That Schmidt's specimen of F. facunda was a decidu- 

 ous one is proved (if I am right in considering that the re- 

 appearance of the sexradiate spicules (PL XVII. fig. 4) only 

 takes place after death) by his description and delineations, 

 wherein he both states and shows that the vitreous fibre was 

 built upon sexradiate spicules, and also shows that the speci- 

 men which was submitted to him for examination was accom- 

 panied by the isolated forms of spicules peculiar to the species, 

 which he has also represented ; so was the deciduous specimen 

 of Aphrocallistes Bocagei " No. 36 " dredged up on board 

 H.M.S. ' Porcupine,' although not that dredged up on board 

 the ' Noma ' by Mr. Kent, of which nothing was left but 

 the vitreous structure. 



It will be remembered that at p. 446 I have stated that 

 Dr. Bowerbank had confounded two species of Farrea in his . 

 illustrations of F. occa (P. Z. S. 1869, pi. xxiv. figs. 1 & 7) ; 

 also that both had been previously noticed and illustrated by 

 Prof. Owen in 1857 (Trans. Linn. Soc. I. c.) ; further that the 

 " retentive spicules " figured by Dr. Bowerbank as charac- 

 teristic of Farrea occa do not belong to the sexradiate system 

 of sponges, but probably to some undescribed species of 

 Oummina. 



In order that I might fully satisfy myself of these points I 

 (at the kind suggestion of Dr. Farre) took for deliberate 

 examination fragments of these two species of Farrea, 

 which abound, in a deciduous state, in the mass of detrital 

 material in which the anchoring -spicules of his specimen 

 of Euplectella cucumer are imbedded. These, which 

 altogether would not fill a cubic space of -fa inch, were 

 boiled in nitric acid ; and the larger fragments having been 

 taken out, the rest was well washed, dried, and mounted 

 in Canada balsam. To a short description of the latter I 

 shall return presently ; in the mean time let us turn our atten- 

 tion to the specimens of the two Farrece ; and as already F. occa 

 has been described, we have now only left the new species 

 which stands in Prof. Owen's and Dr. Bowerbank's illustrations 

 respectively under the figures "8" and "1." To this species 

 I intend to apply the term " densa" on account of its massive 

 reticular structure, which is just the opposite to that of Farrea 

 occa , whose general form is tubular, branched, and only one 

 layer thick. While, however, nothing remains of this sponge 

 also but its deciduous skeleton, still the general character of 

 this and the peculiar character of the fibre of which it is com- 

 posed appear to me, although necessitating a very short de- 



