f>38 dr. J. s. bowerbank on [June 20, 



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 1 Surface even. Osculaand 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. 



Hah. West Indies {Captain Hunter, R.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 

 my friend, Mr. J. Deane, for my possession of it. It was received, 

 with other siliceo-fibrous specimens of Sponges, from Captain Hunter 

 by my 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 cha- 

 racteristic. 



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 fur- 

 nished 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,wbieh 

 are occasionally terminated by slender more or less perfect rectangu- 

 lated 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 



