ART. 4 SPOXGES OF CALIFORNIA DE LAUBENFEL.S 71 



confused it with OphUtaspong^ia pemmta (which see) ; but in addi- 

 tion to the differences between the sponges there is also a difference 

 in the habitat, the two overlapping little if any. As noted elsewhere, 

 pennata occurs nearer high-tide mark than any other sponge of 

 which I know, usually on the sides of bowlders beneath pendant 

 seaweed. E. oHginulis occurs very near low-tide mark and also be- 

 low it, usually underneath stones. It also grows loose and unat- 

 tached or on coralline algae. It is moderately common in central 

 California, and on March 14, 1926, I found several small patches 

 of this species encrusting rocks intertidally at Laguna Beach. 



Description. — Shape, massive. Size, 2 by 3 by 7 cm. Consistency, 

 stiff, slightly compressible. Color in life, light brownish red; pre- 

 served, pale drab. Oscules, round, not raised ; diameter, up to 2 cm. 

 Tlie oscules are largest and most frequent where the sponge is 

 thickest. One small, undamaged specimen brought into the labora- 

 tory. July 2, 1926, exhibited strong oscular currents, tall transparent 

 protoplasmic " chimneys " being thrown up above the surface by 

 the force of the stream. They were contractile, at times reducing the 

 size of the actual opening to far less than that of the canal or cloaca 

 below, without shortening much if at all. In this sponge the cloacal 

 tubes were about SOOyu, in diameter, and the chimneys raised also 

 about 300/A above the surface. Pores, not evident; clearly the}'^ must 

 be exceedingly minute. Surface, superficially very smooth. 



Ectosomal specialization, a dermal membrane only 2/a to 5/* thick; 

 detachable, fleshy, contains probably but one cell layer and seemingly 

 no spicules. Endosomal structure, a very regular reticulation of 

 strong fibers perpendicular to the surface, containing a little spongin 

 and many rows of styles, points almost always toward the surface. 

 The connectives are merely single spicules, however, but placed 

 almost as symmetrically as the rungs of a ladder. Histological de- 

 tails : The subspherical flagellate chambers are about 30/a in diame- 

 ter. Ascending fibers, 25^ to 35/;i in diameter and about 150/* apart. 

 Accessory, or transverse, fibers, single spicules only. 



Principal spicules, subtylostyles (fig. 38, J., 5) ; size, 12/^ by 150/i 

 to 13/i. by 155/x.. Microscleres, palmate isochelas (fig. 38, C, D) ] 

 length, 13/A to 16/i. 



Remarhs. — Comparison between this species and Ophlitaspongia 

 pcrmata is interesting. N'either is typical of the genus in which it is 

 nctw placed, and either could be shifted over to the other genus with- 

 out violence. The tAvo species are easily separated when the micro- 

 scleres are to be found, however, as the one has only chelas where the 

 other has toxas. E. originalis has also much smaller magascleres. 

 The colors are not quite the same, originalis having a rather brownish 

 tinge where pennata is clear bright red. 



