460 DR. J. S. BOWERBANK ON [JunC 5, 



botli series abundantly laden with externally adherent particles of 

 extraneous matters. 



Colour. In the dried state, light ochreous yellow. 

 Hab. Geelvinks Bay, New Guinea (Dr. A. B. Meyer). 

 Examined in the dried state. 



Type in the Dresden Museum. 



Dr. Meyer observes, "in life brown." 



The form of this sponge is that of a contorted fan six inches high 

 by eight and a quarter inches broad. It is based on a short massive 

 pedicel. The thickness of the general expansion of the sponge does 

 not at any part exceed one twelfth of an inch ; and the general con- 

 struction of the skeleton is visible to the unassisted eye. It has lost 

 a great part of its dermal membrane ; but considerable portions of it 

 still remain. It is destitute of any spicula usually characteristic of 

 dermal tissues ; but it is abundantly supplied by adhesion with 

 adventitious spicula of other sponges and of grains of sand and other 

 such matters. The oscula are scarcely distinguishable ; they appear 

 to consist of minute orifices rarely exceeding the size of one of the 

 areas of the skeleton-rete, and they are very irregularly distributed 

 over the inner or concave surface of the contorted sponge. I could 

 not detect any pores in a portion of the dermis mounted in Canada 

 balsam. 



The loosely constructed polyfibrous lines of the skeleton are very 

 singular in their structure. They consist of numerous minute fibres, 

 running nearly parallel to each other, and anastomosing at irregular 

 intervals by short connecting fibres at nearly right angles to each 

 other. Neither the primary nor the secondary lines ever appear to 

 be in any degree twisted. The primary lines, on an average, 

 measured yL inch in diameter, and the minute fibres of which they 

 are composed varied frem ^^^^ to yy^yj ^^^^^'^ in diameter. 



The interior of the sponge appears to be as abundantly supplied 

 with adherent grains of sand and other adventitious substances as 

 the dermal membrane is ; but none of such substances were embedded 

 in the keratose fibres of the sponge as in the genera Halispungia or 

 Dysidea. 



4. Halispongia stellifera, sp. nov. 



4. Sponge cup-shaped, compressed, parietes thin, pedicel short. 

 Surface even and smooth. Oscula small, slightly raised on low 

 tumid elevations, few in number. Dermal membrane pellucid, aspi- 

 culous, but abundantly supplied with adherent extraneous matters. 

 Pores disposed in areas containing from one to two or three of them, 

 each surrounded by numerous minute radiating fibres anastomosing 

 near the pore, but diverging separately towards their distal termina- 

 tions. Skeleton : Primary lines radiating in nearly parallel lines 

 from the base to the distal margin ; secondary lines anastomosing 

 irregularly with the primary ones. Primary and secondary lines 

 ■ 1- 4,,> both polyfibrous; fibres solid, cylindrical, frequently anastomosing 



'• " ~ irreguTarly. Ge'mmules minute, spherical, dark and opaque. 



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