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Show f>38 DR. J. S. BOWERBANK ON [J I have compared the structures of this sponge with other nearly allied species without being able to assign it to any one of them. From the paucity of its armature I have designated it, specifically, inermis. FARREA PERARMATA, Bowerbank. (Plate LVII. figs. 1, 2.) Sponge cup-shaped ? Surface even. Oscula and pores unknown. Dermal system reticulated ; primary and secondary fibres cylindrical, disposed at right angles to each other. Areas of the rete mostly quadrilateral, occasionally oblong; fibres profusely furnished with minute conical spinules ; canals of the fibres obsolete ; areas of the rete frequently furnished at their angles, both at the external and internal surfaces of the inhalant surface, with large imbricated conical defensive organs, frequently terminated with rectangulated sexradiate organs of defence ; also with numerous separate slender rectangulated sexradiate defensive organs and single long and slender spinulated spines, based on the skeleton-fibres, and occasionally with rather long and slender attenuated spines based on the fibres between their angles in cruciform arrangement. Nearly all the defensive organs more or less spinulous. Colour unknown. Hab. West Indies (Captain Hunter, B.N.). Examined in the dried state. The only specimen I have seen of this sponge is a fragment of what has apparently been a portion of a very delicate siliceo-fibrous cup. It is seven lines in length and five lines broad. I am indebted to m y friend, Mr. J. Deane, for m y possession of it. It was received, with other siliceo-fibrous specimens of Sponges, from Captain Hunter by m y late friend, Mr. Henry Deane, of Clapham. The fragment is slightly curved in one direction, inducing the belief that it has formed a portion of the sides of a rather expansive cup-shaped sponge. There are not the slightest remains of either membranous structures or of sarcode on any part of the well-washed specimen. The skeleton of the sponge only remains ; but this is fortunately remarkably characteristic. The primary and secondary lines of the skeleton are nearly or quite equal in size, and they are generally disposed at right angles to each other, so that the areas are usually square or more or less oblong. All parts of the skeleton-rete are profusely and rather regularly furnished with minute conical spinules ; and not the slightest indication of the presence of central canals could be detected in any part of the skeleton-structures. The angles of the skeleton-rete, both externally and internally, are frequently armed with stout imbricated conical defensive spines,which are occasionally terminated by slender more or less perfect rectangulated sexradiate defensive organs, which are rarely quite smooth, but more frequently amply supplied with minute conical spinules. The rectangulated sexradiate defensive organs are also often projected from the skeleton-fibres without the intervention of the large imbricated |
