REPORT ON THE KERATOSA. 57 



their whole extent, and, in spite of my endeavours to discover any initial or further 

 stages in their development, I find these oval bodies enclosed, though differing in size but 

 always with precisely the same external appearance. I believe they belong to some low 

 plants. 



Colour. — Outer surface black, parenchyma dirty yellowish-grey, skeletal fibres 

 bro\\Tiish-yellow. 



Habitat. — Off Barra Grande, September 10, 1873; depth 400 fathoms, red mud. 



Cacospongia amorpha, n. sp. (PI. VI. fig. 5). 



The properties of the skeleton of this species recall those of Eusp>ongia officinalis, var- 

 lobosa, as regards the tendency of the primary fibres to ramify, but the fibres, both primary 

 and secondary, are comparatively far larger, as are also the meshes formed by them ; one 

 might illustrate the difi'erence between these two forms by comparing them to a bush and 

 a tree. 



The species is represented by two specimens, one of a massive stout appearance, the 

 other 100 mm. high by about 20 mm. thick, of roundish outline in the upper part, 

 and flatly compressed near the rather extended bases. The outer surface is denticulated 

 by prominent primary fibres forming conuli of 1 mm. on an average, and 3 to 5 mm. 

 distant from one another. In many instances the membrane between the conuli is not 

 homogeneous but sieve-like, the pores being very conspicuous. All the primary fibres are 

 overcharged with foreign bodies, this property rendering them of irregularly angular 

 outline ; some of the secondary fibres are devoid of any enclosures, others on the contrary 

 being more or less covered with saud-grains, fragments of spicules, &c., and often a fine 

 secondary fibre shows an extension in its middle, owing to the presence of a sand-grain 

 many times larger than the diameter of the fibre itself. It may also be added that, as 

 in Hircinia variabilis according to F. E. Schulze,^ the primary fibres in my Cacospongia 

 amorpha show a tendency to form meshes. 



Colour. — Outer surface grey, parenchyma butter-like, skeletal fibres pale brownish- 

 yellow. 



Habitat. — Bahia, shallow water. 



Cacospongia murrayi (PL IV. fig. 3 ; PI. VI. fig. 8). 



It is really very agreeable, after such a bad species as that just described, to pass on to 

 the description of such a bona species as Cacospongia murrayi. The single speci- 

 men on which this species is founded is represented on PL IV. fig. 3, the skin of one 

 part being stripped off. The external surface is smooth throughout, and is represented 

 by a rather thick dermal membrane, which, owing to the great number of foreign 



1 Zeitschr.f. wiss. Zool., Bd. xxxiii. pi. iii. fig. 1, 1880. 

 (ZOOL. CHALL. EXP. — PART XXXI. — 1884.) Hh 8 



