REPORT ON THE KERATOSA. 61 



Cacospongia spinifera, n. sp. (PL VI. fig. 12). 



Had the genus OUgoceras been retained it would have been necessary to refer the 

 species I am going to describe to that genus. The outer surface of the single specimen 

 representing this new species in the collection is indeed a contrast to OUgoceras collectrix, 

 being quite devoid of any foreign bodies, but they are abundant in the parenchyma, 

 and on the other hand are so richly represented in the skeletal fibres that these latter 

 are extremely poor in true horny substance. Again as to the external aspect of its 

 skeleton, — apart from the point that it is not represented by isolated standing trees as 

 in OUgoceras collectrix, — it recalls vividly that of the form just mentioned. The large 

 size of the meshes, the tendency of the fibres to ramify — all this approximates the form 

 I am now describing to Cacospongia {OUgoceras) collectrix. There is, however, a 

 character which permits a pretty sharp diagnosis of the species ; I mean the nature of 

 its outer surface. The latter, in spite of the great friability of the skeleton and its general 

 tendency to disappear entirely, is still provided with very high conuli (4 to 7 mm.), so that, 

 if drawn, this specimen would give precisely the same impression as the drawing given by 

 Hyatt for his Hircinia acuta,^ and this not only with regard to the character of the outer 

 surface, but also that of the external shape of the sponge in general. The specimen 

 must have died at the moment when its dermal pores were open, and thus the whole of 

 its outer surface is of a sieve-like appearance in the proper sense of the word. Apart 

 from the point that, like the preceding form, this specimen proved to be overloaded with 

 filaments, their heads being of elongated form and reaching 0"06 mm. in length and 

 0'04 mm. in breadth on an average, there are no histological nor anatomical peculiarities 

 of interest to be stated. 



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

 black. 



Habitat.— Station 177, August 18, 1874, lat. 16° 45' S., long. 168° 7' E. ; depth 

 130 fathoms, volcanic sand. 



Cacospongia tuherculata, n. sp. 



So far as the properties of the skeleton are concerned (apart from the fact that the 

 fibres are not black but pale yellow), this species seems to be closely allied to Cacospongia 

 spinifera. Indeed, in most cases the primary fibres do not ramify at aU, but ascend 

 vertically, and are united with one another by horizontal secondary fibres, these latter, as 

 in Cacospongia spinifera, beginning very often with flat extensions ; yet, here and there 

 ramifying fibres have been found, their secondary obliquely directed branches instead of 

 reaching the neighbouring primary fibres ending freely. There is, however, one character 



' Revision, &c., vol. ii. pi. xv. fig. 20. 



