^S77.] FIVE NEW SPECIES OF SPONGES. 461 



Colour. In the dried state, grey ochreous yellow. 

 ffab. Geelvinks Baj', 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 closely compressed cup 

 with a considerable complication of parietes on one side ; and it 

 does not appear as if it had been more expanded when in the living 

 condition. It is one foot in height and the same at its greatest 

 expansion, and the pedicel is short and stout. When covered by the 

 dermal membrane, the surface both within and without the cup is 

 smooth and even. Near the base of the sponge there are a few 

 oscular orifices slightly elevated on tumid masses ; but these organs 

 are inconspicuous on the more fully expanded parts of the sponge. 

 When a portion of the dermal membrane, mounted in Canada balsam, 

 was examined by transmitted light with a power of 200 Hnear, the 

 porous areas seen were large and well defined ; they contain usually 

 one, but occasionally two or three pores, each of which is surrounded 

 by a beautifully regular and very extensive series of apparently 

 minute corrugated radiating hues ; some of these pores are open, 

 while others are completely closed. With a higher power this ap- 

 parent corrugation is seen to consist of minute slender transparent 

 fibres which freely anastomose with each other in the immediate 

 neighbourhood of the pores ; but subsequently they diverge freely to 

 a very considerable distance from the pore without anastomosing 

 with each other. 



The skeleton is decidedly that of a Halispongia. The primary 

 or radial fibres are amply supplied with the usual central lines of 

 embedded grains of sand and other extraneous substances, and more 

 especially so at the surfaces of the sponge. A few adventitious 

 spicula of various sizes and forms are entangled amid the skeleton- 

 fibres, to which also numerous dark opaque spherical gemmules are 

 attached, varying in diameter from ^(y-oij to j-J^ inch in diameter. 



The most striking specific characters in this species of sponge are 

 undoubtedly those of the dermal membrane ; and it must be observed 

 that they are very difficult to find without the aid of mounting 

 portions of the dermis in Canada balsam ; and from the extreme 

 delicacy of the radial lines surrounding the pores, powers of from 

 200 to 500 linear are required to render them distinctly to the eye 

 of the observer. 



5. Hyalonema anomalum, sp. nov. 



Sponge expansively cup-shaped, sessile (?) Surface smooth. 

 Oscula on the inner or exhalant surface, simple, large and numerous. 

 Pores dispersed, inconspicuous. Dermal system expansible ; con- 

 necting spicula expando-quaternate ; radii and shaft attenuating, 

 large and strong. Dermal membrane aspiculous (?). Skeleton : 

 Cup compressed (?), fasciculated, fasciculi loosely compacted; spi- 

 cula cylindrical, with clavate or thyrsiform terminations incipiently 



