446 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



0.5 to something over 1 mm. high, 0.5 to 1 mm. apart. The outer 

 surface of sponge is roughened by numerous elevations, which in 

 the alcoholic specimen are irregular in shape, but in the dried speci- 

 men are short subcylindrical lobes projecting upward and outward j 

 such lobes are mostly 10-15 mm. high and about 5 mm. in diameter,, 

 grading away into slight irregular protuberances. Surface of cloaca 

 lacks the elevations which make the outer surface so uneven. 



A few pores are distinguishable in the alcoholic specimen ; doubt- 

 less most are closed ; the open pores are scattered over both surf aces,, 

 where they perforate the thin dermal membrane and lead directly 

 into the subdermal cavities which are of moderate size. Oscula 1 to 

 4 mm. in diameter are scattered over both surfaces; they are larger 

 and more abundant in the dried specimen than in the other. 



Skeletal framework consists of ascending spicular tracts inter- 

 woven so as to form a loose irregular reticulum which nearly fills 

 the whole sponge body, breaking up close to each surface into short 

 obliquely radial tracts which enter and support the conuli and con- 

 necting ridges. The spicules of a radial tract separate so that a 

 conulus contains a very few spicules, usually only two or three and 

 sometimes only one (pi. 49, fig. 9). Spongin very scanty and the 

 tracts of the main skeleton thus not well defined; these tracts 150- 

 250 [x thick and crowded, the meshes between them often 300-100 

 pi wide, longer than wide. Between the tracts of the main reticulum 

 lie scattered spicules, which close to the surface may assume a 

 tangential position, thus extending between the radial tracts where 

 the latter enter the conuli. The short radial tracts of this species 

 may be taken to represent the radial fibers of axinellids in which the 

 skeleton is distinctly differentiated into an axial part and a periph- 

 eral part. 



Spicules. — Oxea (pi. 49, fig. 9), equiended, cylindrical, smooth, 

 slightly curved, sharp pointed; 1000-1500 by 30-40 \l. Slender, 

 young forms of course occur. A very few styles occur, intermingled 

 with the oxea, but no more than might be expected to occur through 

 variation in any sponge with diactinal megascleres. Another varia- 

 tion occurs, rarely, in both specimens; in this type the oxea is not 

 evenly curved, but is sharply, although not much, bent at some point 

 which is usually not the middle, the spicule hence asymmetrical. A 

 third variation, which may be looked on as an intensification of the 

 last occasionally occurs in one (the dried) specimen; the oxea of 

 this type is curved at several points, thus becoming serpentine; such 

 spicules were found in the interior, perhaps serving as binders; they 

 correspond to smaller sizes of the typical spicule, a characteristic 

 one measuring 500 by 10 p.. 



