532 HYATT'S REVISION" OF THE 



The walls of the tubes are made up of vertical fibres not ver}^ wide apart, and connected 

 by closely approximated secondary fibres. The primary fibres are gathered into groups 

 of two or more, standing in the same plane, though occasionally, at the corners of the tubes, 

 solid groups are formed by the branching of the fibres ; then either new tubes arise be- 

 tween the branches, or solid fiisces are formed, as in Stelofij^oncjos Maynard'd. The form, 

 instead of being solid and crest-like, as in variety stab'dls (Key West specimen), is like 

 that of the Havana representative of that variety. 



Loc, Havana and Hayti, in Mus. Comp. Zool., and in Soc. Coll. 



Stelospongos Pikei Hyatt. 



The skeleton of this species is represented by many beach-worn specimens collected at 

 Mauritius by the English Consul, Col. N. Pike, [Coll. Mus. Comp. Zoology and Soc. Coll.]. 

 They are highly colored, of a yellowish brown hue, and very hard and inelastic. The sur- 

 face presents the aspect of S^jougelia. The fibres are apparently single, and project in the 

 form of stiff bristles, about 5 mm. long, where they have not been worn off by friction 

 on the beach (PL xvii, fig. 20). The tissue between is dense, and is penetrated by 

 apertures of variable size, irregularly scattered over the surface. Upon closer examination, 

 it becomes apparent that most of the fibres are not single, but really compound bundles. 

 The fibres composing these may be so closely joined in the interior that it requires critical 

 examination to detect their compound chai-acter, or they may be quite wide apart. 

 The connecting tissue of secondary fibre has a very close and dense, but irregular mesh, 

 resembling in this respect the connective tissue of Verongia Jistularis. In some parts of 

 some specimens a very remarkable and characteristic variation was observed, similar to the 

 Diteliform variation of the surface previously described. A web of very fine white fibres 

 crosses the larger meshes, and connects the dark yellow, horn colored fibres of the original 

 skeleton. This is so fine and so dense that it has a downy or fleecy look on the cut surface 

 of a section. 



Stelospongos intertextus Hyatt. 



This species is represented by only one specimen, in the Collection of the Museum of 

 Com2>arative Zoology, from the Mauritius. It resembles Spomjelia enormis in form, but 

 has only a few scattered excurrent orifices on the dried skeleton. The texture is remark- 

 ably light, and very closely resembles that of Spongelia. Upon close examination, how- 

 ever, it can be seen that the primary fibres branch frequently ; that these branches run 

 parallel for a considerable distance and are loosely united by short secondary fibres. The 

 general connecting tissue of secondary fibres resembles the irregular texture of some spe- 

 cies of Spongelia in which no very distinct tubes are formed. The arrangement of the 

 primary fibres on the surface, at first led me to suppose that this might be the young of 

 some variety of Spongelia e)iormls. If the primary fibres were single, I should not feel 

 justified in separating it; but I have not, however, so far found that the compound charac- 

 ter of the fibre is a characteristic of the young of either Spongelia or Spongia ; and, there- 

 fore, until we know more of the animal, it seems to me safest to classify the debateable 

 species according to the character of their primary fibres. Thus, though this is a true 

 Spongelia in general aspect, lightnesss and elasticity of texture and form of the mesh of 

 the general tissue of secondary fibres, I prefer to consider it a member of the genus Stelo- 

 spongos on account of the characteristics of the primary fibres. 



