REPORT ON THE KERATOSA. 71 



specimen, proved to be full of spermospores. To a more detailed description of these 

 latter I shall return later, and will now merely call attention to this peculiarity of the 

 skeletal fibres of my Verongia hirsuta, that they almost all proved to be covered with 

 small plates of polygonal outline as represented on PI. X. fig. 3 ; I have been unable to 

 make out their origin. Occasionally, and particularly on young fibres, I found no such 

 plates, but small drops of yellow substance at a comparatively great distance from one 

 another. I can but state, and this with the greatest certainty, that these plates are 

 not modified spongoblasts. I regard them as the last product of the spongoblasts, ready 

 to lose their spongoblastic properties in order to become common stellated cells. 



CoZoztr.— Pale rose-brownish, skeletal fibres dark brown. 



Habitat. — Ofi" Bermudas, June 1873; reefs. 



Verongia tenuissima, Hyatt (PL X. figs. 4-7). 



Verongia tenuissima, Hyatt, Revision, &o., vol. i. p. 403. 



Hyatt's work upon the Keratosa is so very poor in explanatory illustrations that 

 although the short diagnosis he gives to his Verongia tenuissima is entirely applicable to 

 the form I am going to describe, I do not feel quite certain whether both these forms are 

 identical, but if not, at any rate they are very closely allied to one another, and to be 

 probably distinguished merely as diflerent varieties of the same species. 



The form is represented by a single specimen. It is of fistular shape, the central 

 cavity being funnel-like, with a circular upper extension of 22 mm., and the walls 20 mm. 

 thick in the basal and middle parts of the body, growing rather thinner towards its 

 upper end. The inner surface, in contrast to that of Verongia hirsuta, is smooth but 

 undulating, while the outer surface is hilly ; the surface both of hillocks and depressions 

 being shagreen-like, and studded wdth projecting points of the skeletal fibres. These 

 latter — in thorough harmony with Hyatt's statement on the point — are far thinner and 

 more elastic than those of Verongia Jistularis, yet at least one and a half times as thick as 

 the fibres of Ai^lysina aerophoha; their average diameter is 0"2 mm., and the meshes 

 formed by them recall vividly in size and shape those of Aplysina. The internal 

 organisation, both anatomical and histological, agrees so closely with that of Ajilysina 

 aerophoha that having illustrated it l)y a small drawing (PL X. fig. 7), I can refer the 

 reader to F. E. Schulze's paper on the Aplysinidse. I must add, however, that I was not 

 able to discern the bundles of fibrils which he describes ^ and represents on pi. xxii. 

 fig. 14. of his paper. But I was fortunate enough to discover the male generative product, 

 the spermospores ; and this both in Verongia hirsuta and Verongia tenuissima, in this 

 latter form together with ova, scantily scattered in the peripheral parts of the body, 

 while the spermospores have been found everywhere and in abundance. I call them 



1 Zeitschr.f. wiss. Zool, Bd. xxx. p. 397. 



