44 THE AUSTRALIAN MUSEUM. 



Test stiff and leathery, of a dirty white colour inside. 



Mantle thick, pigmented with minute brown dots, not very muscular, 

 prolonged for a short distance down the stalk. 



Branchial sac is thick, and of a dark brown colour. The 3 folds next 

 the endostyle on each side are rounded pad-like projections ; the 4th is 

 more distant, and does not project. The bars and vessels are thick and 

 numerous, and the stigmata are very narrow. There are about 3 

 stigmata in a mesh. 



Dorsal lamina a narrow membrane, beset with minute papillae. 



Tentacles short and stout, about 24, and of a dark brown colour, with 

 much smaller intermediate ones. 



Dorsal tubercle large, and spongy in appearance. 



Gonads numerous elongated polycarps. 



Locality. Moreton Bay; one specimen. 



This is, perhaps, the most remarkable of the new Polycarpas, and its 

 extraordinary form (PI. Cyn. XVI., fig. 1) almost warrants the creation of 

 a new genus. It is like a black fungus in appearacce. It is stiff in all 

 parts, and slightly sandy on the stalk (fig. 2). The test is marked with 

 slight lines or creases running circularly around it (figs. 1 and 2). When 

 the test is removed (fig. 3) the positions of the branchial and atrial 

 apertures are seen with their conspicuous sphincters. The posterior 

 prolongation of the mantle seems to run for a short distance only into 

 the stalk. The mantle is from 1 mm. to 3 mm. in thickness, and the 

 curious polycarps project from its inner surface (figs. 4 and 5). The 

 polycarps are slightly constricted at the base, then sausage-like in form, 

 and finally taper, so that the upper end has a conical form. They are 

 pigmented at the tip, and dotted all over (fig. 5). 



There are unusually strong connectives between the mantle and the 

 branchial sac. The branchial sac is remarkably thick and opaque (figs. 

 6, 8). The 3 ventral folds on each side are rather near the endostyle, 

 which forms a conspicuous pad, with a very narrow slit between 2 

 swollen lips. 



The dorsal fold on each side is not a projection, but is merely 12 

 internal longitudinal bars massed together, recalling the condition in 

 titijclopsis yrossularia. The fine vessels between the stigmata are tra- 

 versed by bundles of muscle fibres (fig. 7), which divide and anastomose 

 in the transverse vessels. On the back of the branchial sac all the 

 larger vessels, both transverse and longitudinal, bear numbers of small 

 papillae, irregularly placed (fig. 8). 



The dorsal lamina (fig. 9) is also papillated irregularly on its surface. 



