186 Mr. S. O. Ridley on Sponges. 



Colour, in dry state, orange-brown. Skeleton — composed 

 of long, imperfectly separated bands of the skeleton-spicule, 

 massed closely together and parallel in direction, extending 

 from the base towards the apex of the lobes composing the 

 sponge, beneath the layer which forms the immediate sur- 

 face. Dermal layer consisting of short spicular columns, '4- 

 •6 millim. in height, arising vertically or obliquely to the 

 surface, where the spicules spread out so as to form, by the lateral 

 divergence of their apices, brushes, which are in contact with 

 each other laterally ; between the bases of these brushes are 

 placed the chones of the inhalent canal-system. Spicules — 

 spinulate, smooth, head oval to globular, a small basal 

 rounded prolongation in nearly all spicules, except those fully 

 adult, where it appears usually to be wanting ; neck mode- 

 rately distinct ; shaft normally straight, tapering to a sharp 

 point from near middle : size — main skeleton "8 millim. by 

 •019 millim. (both head and shaft), dermal skeleton '<o by '013 

 (head), '0095 millim. (shaft). Internal soft tissues transpa- 

 rent and pale amber-yellow in the dried state. 



Hah. Adriatic {Schmidt) ; Mauritius {coll. Mus. Brit.). 



This form agrees in every essential particular of its minute 

 structure with Adriatic specimens. 



Mr. Carter (Ann. & Mag. Nat. Hist. ser. 5, ix. 1882, p. 351) 

 records from Mauritius a Suberites, as " massive, growing 

 into short branches on the surface ; colour ochre-yellow." 

 He says it is undescribed, but shortly afterwards states that 

 it will probably be found to be identical with the above 

 species. 



The laminffi in the present specimens appear to be more or 

 less distinct from the base upwards. The total height of the 

 sponge is about 60 millim. (2^ inches) ; horizontal extent of 

 the largest specimen (apparently not quite perfect) 110 by 

 78 millim. (4^ by 3 inches). 



Since the above description and remarks were written, 

 another specimen of this species has been received, also from 

 Mauritius, which is composed of similar vertical laminge ; 

 these, however, instead of being closely appressed by their 

 sides, are distinct from each other, with the exception of junc- 

 tions caused by uniting trabecule of sponge-substance ; thus 

 the common portion of the sponge forms a honeycombed mass 

 with wide fenestra ; above, the vertical plates project freely in 

 the form of flat plates, sometimes of considerable extent, or 

 of narrow finger-like lobes, closely resembling those of the 

 Adriatic specimens of the species now in the British Museum. 

 In this second Mauritius specimen the subglobose form of tlie 

 head of the spinulate is the commonest, and the horizontal 



