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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 81 



DesGription. — Shape, amorphous, massive, encrusting. Size, 2.5 

 mm thick, 3 or 4 cm in diameter. Consistency, mediocre, spongy, 

 fragile. Color in life, orange; preserved, drab. Oscules, not evi- 

 dent. Pores, not evident. Surface, superficially between smooth 

 and minutely tuberculate. 



Ectosomal specialization, a dermal membrane about 80/x thick, 

 not detachable, containing characteristic dark cells. Endosomal 

 structure, fleshy; the canals are few and inconspicuous, asters are 

 very abundant, and there are scattered tracts as described below. 

 At the surface the tracts spread into terminal brushes. Principal, 

 or ascending, tracts 100 to 125/x, in diameter, consisting of densely 



Figure 21. — Timea authia de Laubenfels : A-F, X300; others, X 1,333 



packed monaxons, points upward. These tracts ascend to the sur- 

 face at an angle. They are about 600/x apart. 



Principal spicules tylostyles (fig. 21, D) ; size, about 10/x by T70/x. 

 Secondary spicules, styles (fig. 21, E, F) ; size, 4/t by 200/i, to 11/x 

 by 840/x. Microscleres, tylasters (figs. 21, A, B, C, G-L) ; diameter, 

 6/x to 23/x, located throughout the sponge. These spicules vary from 

 smooth to minutely roughened. Some have 20 to 30 rays, others 

 10 or less. Some are so enlarged at the base that the appearance is 

 of spherasters, others clearly have no centrum. The tylote termina- 

 tion seems consistently present. 



Rertiarks. — Timea Gray (1867, p. 544), type T. stellata, receives 

 as synonym Columnitis Schmidt (1870, p. 25), type C. squamata, 

 and both are often merged in further synonymy with Tethya. After 

 a study of the California specimens of each, I feel it most accurate 

 to retain Timea and Tethya separate. Local conditions are so very 



