BY E. F. KALLMANN. 359 



many, usually branched, stout, root-like processes. The fistu- 

 lae are, almost without exception, widely open at their distal 

 end, thv^ugh this appears to be due to their having had the 

 extremity broken off. The roots are tapered, and convey the 

 impression that they serve the function of anchoring the 

 sponge in mud ; according to the original description, they 

 may attain to a length of 300mm. The largest specimen (PI. 

 XX., fig. 2) is of comparatively irregular form, being elongat- 

 ed in one horizontal direction, and compressed at right angles 

 thereto; it measures 230mm. in length, by 180mm. in height; 

 and (though only a half-specimen) is provided with about a 

 dozen roots. 



The original description states that, in addition to fistulae, 

 there occur on the upper surface of the sponge, at its centre, 

 two to five much wider and shorter tubes, 20mm. wide and 

 only 25mm. high, the cavities of which are occupied by a reti- 

 cular structure : unfortunately, in the type-specimens, owing 

 no doubt to their not being symmetrical halves of the origi- 

 nals, none of these tubes are present. It happens, however, 

 that the trawling steamer "Endeavour" has recently obtained, 

 from off the coast of New South Wales several specimens of a 

 sponge closely related to rhheodictyon ramsayi — I propose to 

 designate it a variety, pyrifoi^mis , of this species — which pro- 

 vides the clue to the nature of these tubes. 



The variety is a stoutish, pear-shaped sponge without roots, 

 which evidently, in life, was attached by its narrower end to 

 a hard substratum. The fistulae, which are short and stout, 

 are usually not numerous, and may be altgether absent ; as, in 

 the only specimens so far obtained, they are all more or less 

 damaged, it is not known whether their extremities are open 

 or closed. A characteristic feature of the sponge is the 

 arrangement of its oscula (Pl.xx., fig. 3), which open side 

 by side to the number of between 50 and 100, together form- 

 ing a slightly depressed, oval or circular, honeycombed area 

 occupying the centre of the upper surface. This oscular sieve 

 differs from that of the typical form of the species, as describ- 



