NORTH AMERICAN PORIFER^. PART II. 543 



between the branches. The branches, also, are soHd, and have none of the perfora- 

 tions or ribs observed in Carterioapongia perforata, and are about one-twelfth of an inch 

 m thickness. The fibres of the skeleton, however, appear to be of about the same degree 

 of fineness in both, but the aspect of the surfiice in this species is very similar to a sec- 

 tion of wood made through the burrows of the ship worm, whereas no such comparison 

 can be made with C. perforata, the cells being much too irregular in size and shape. 

 Loc, Phillip's Island, Australia, in Soc. Coll. 



Carteriospongia perforata Hyatt. 



The single colonv examined is a flabellate branch arising from a narrow base. This 

 throws oft" other branches as it rises, which anastomose in a most ii'regular manner. They 

 are ribbed longitudinally with branching, continuous ridges, between which are numerous 

 round or elliptical openings, which penetrate to the opposite side. The branches are, in 

 this specimen, about one-eighth of an inch in thickness. 



Loc, Phillip's Island, Australia, in Soc. Coll. 



Carteriospongia? mystica Hyatt. 



The specimen upon which this species is founded, like all the Australian keratose sponges 

 which have come under my observation, is of an exceedingly dark color, the ordinary red- 

 brown. So distinct is this color and the hard woodeny aspect, that an observer can usually 

 pick out specimens from this region without difficulty, though this rule has its exceptions, 

 since there are always some among a large lot of West Indian specimens which are quite 

 as dark colored internally, though perhaps never quite so deeply tinged on the exterior ; 

 whereas in Australian sj^onges the reverse is not infrequent, the internal parts of the skel- 

 eton being lighter colored than the exterior. The fronds in this specimen have combined 

 into an irregular cup-shape with several supporting stems, so that it caiinot be said whether 

 the whole is from one frond, or the anastomosis of several neighboring fronds. The inte- 

 rior is perfectly smooth or rather even, for the primary fibres rise above the surface form- 

 ing a pile or beard, which is quite perceptible without the magnifier. The pores are 

 numerous, and there are no surface channels. These, and the cloaca! ostioles, occur only 

 on the exterior, a I'eversal of their customary distribution in this sub-order. This charac- 

 teristic is also found in Sp. lanxellosa, and in fact the enlarged portion of the outer surface, 

 as figured b}^ Esper, is very similar to the aspect of this sponge, except that the oscules 

 usually lie at the point of junction of a group of more or less radiating canals. I am 

 obliged to consider the determination of the genus as very doul)tful ; it may prove to be 

 a true Spongian upon farther investigation, allied to, or identical with, Sp. lignea. 



Loc, Adelaide Islands, So. Australia, in Yale Coll. 



PHYLLOSPONGIA. 

 Phyllospongia papyracea Eliler. 



PhyJlospongia papyracea Ehler, Die Esper'sch. Spong. Erlangen, 1870, p. 30. 



The peculiar form of the species (PI. xvii, fig. 31), which alone represents this group, is 

 unique. It is flat, like a leaf, and looks and feels like an extremely coarse, thick paper. 

 The surface is dense, owing to the net-like anastomosis of the finer intermediate fibres of 



