SILICIOUS AND HORNY SPONGES WILSON. 311 



features. At any rate, even if the genera so based are artificial, they 

 are to-day useful categories. 



Since Lendenf eld's Tetraxonia (1903), species assigned to Geodhi 

 have been described by Topsent, 1904 (p. 70) ; Dendy, 1905 (p. 85) ; 

 Lendenfeld, 1906 (pp. 328, 333) ; Hentschel, 1909 (p. 366) ; Lenden- 

 feld, 1910 (pp. 55, 79, 96, 113, 151, 155, 161, 170, 175, 181, 188) ; 

 Kow, 1911 (p. 296) ; Hentschel, 1912 (p. 314) ; Lebwohl, 1914 (pp. 42, 

 49, 57) ; Stephens, 1915 (pp. 431, 432) ; Dendy, 1916 (p. 254). 



GEODIA PHILIPPINENSIS. new species. 

 Plate 37, fig. 9; plate 46, figs. 3, 4, 5. 



Station? Locality label missing. A very large vase-shaped 

 sponge, 540 mm. high; mouth of vase 450 by 400 mm.; wall at the 

 top 20 mm. thick, growing thicker below. The vase narrows to- 

 ward the base, having the shape of a truncated, inverted cone; the 

 base itself somewhat expanded, having a diameter of 300 mm. 



The outer surface bears conspicuous radial tufts of spicules, about 

 10 mm. apart. Such tufts are 5 mm. and more in height, 2-3 mm. in 

 diameter at the base, tapering toward the free end. Over a large 

 part of the surface they are broken or worn off. Very many of the 

 spicules composing the tufts are broken at their outer ends; the 

 unbroken spicules are protriaenes with clads 50-70 {jl long and 

 anatriaenes with clads 50-70 \i long.. There is some indication that 

 the outer surface, which now is in general smooth, is naturally 

 covered with a continuous but rather thin furze of similar pro- 

 triaenes and anatriaenes. At any rate, this surface shows such 

 spicules, projecting 3-4 mm., in some spots which have apparently 

 been protected from wear. 



The basal surface, surface of attachment, is not quite flat, but is 

 made somewhat uneven by elevations and depressions. It, too, shows 

 in spots a sparse furze of projecting protriaenes and anatriaenes, 

 like that just mentioned. The cloacal surface is smooth, that is, 

 shows no projecting spicules. 



Color of the surface is whitish gray, varying to a light brown. 

 Color of choanosome a chocolate brown. 



The cortex is slightly under 2 mm. in thickness, the extra-ster- 

 rastral layer (ectochrote) about 0.5 mm. thick, but this layer has in 

 places been rubbed off. 



The dermal membrane and cortical canal system of the two faces 

 of the sponge, outer and cloacal, are alike. Doubtless the outer is 

 the afferent (pore) face; the cloacal, the efferent or oscular face. 



The dermal membrane, on both surfaces of the sponge, is a finely 

 fenestrated membrane in which " pore areas," in the usual sense, are 



