446 Mr. H. J. Carter on the 



vol. xxii. pi. xxi. fig. 9 & 9 a), and not Dr. Bowerbank's 

 figure 1, which we shall hereafter find to belong to another 

 species of Farrea, also illustrated by Prof. Owen (pp. cit. fig. 8) . 

 In short, a cursory inspection of the two figures in Dr. Bower- 

 bank's plate will show that they belong to two different struc- 

 tures, one of which (viz. fig. 7) has smooth, and the other ( fig. 1) 

 spiniferous fibre. The former we shall call " Farrea occa" 

 and the latter " Farrea densa." 



At the time Dr. Bowerbank described Farrea occa (P. Z. S. 

 p. 339, 1869), the only thing known of it was the fragment 

 mentioned; hence it is not surprising that his description should, 

 to say the least of it, be very different from reality. We now 

 know that this smooth rectangular fibre belonged to a branched, 

 tubular skeleton, only one layer thick, and the branches patu- 

 lous at the ends, which, up to this time, appears to have been 

 found only in a deciduous state ; so that Ave do not know even 

 now what were the forms of the spicules on which the fibre was 

 originally deposited, except through the means already stated, 

 viz. the absorption of these spicules, which takes place only in 

 the deciduous skeleton, reducing their forms to mere moulds, 

 which, however, represent their true forms inside the fibre. 

 Can we find, then, sufficient of these forms enveloped in the 

 deciduous fibre to tell us what the living species possessed ? 

 will be the question by-and-by, when we come to consider 

 Farrea occa more particularly. 



The next specimen which I have had for observation is that 

 of a dead Aphrocallistes Bocagei in a jar without label ; but 

 finding only one place where this sponge is mentioned in the 

 " Preliminary Report of H. M.S.' Porcupine,' " published in the 

 Royal Society's ' Proceedings' (No. 121, p. 424, 1869), where 

 it is stated that a " tolerably perfect though dead specimen of 

 Aphrocallistes Bocagei had been dredged up at Station 36 in 

 725 fathoms with a bottom of muddy sand," I presume that 

 it is the one in question, which consists of a hollow cylindrical 

 tube, composed of vitreous network, closed at the free end by 

 the same structure in a convex form, and terminated at the 

 other by a flat disk, which adhered to the object on which it 

 grew, covered with buds or shorter tubes of a like kind, whose 

 cavities respectively are continuous with that of the main tube 

 or stem, the whole specimen being about two inches long and 

 one in diameter. This " Station," I see by the table, was 

 in lat. 48° 50' N., and long. 11° 9' W. ; so that it was dredged 

 up close to the specimen of Farrea occa just mentioned. We 

 will designate it by the " Station," viz. " No. 36." 



From the deep-sea specimens of H.M.S. ' Porcupine,' let 

 us go to those in the British Museum dredged up on board 



