124 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 81 



Remarhs. — This genus has often been called SpongeUa^ but Spon- 

 gelia of Nardo, 1834, is a nonien nuden. It is first described by John- 

 ston (1842, p. 185) as Duseideia or (preferably) Dysidea. The 

 genus falls rather sharply into two divisions, fine-surfaced grays 

 and coarse-surfaced purples. The first includes the genotype, D. 

 fragilis Montagu. The second includes 'pallescens Schmidt, the geno- 

 type of Spongelia according to Vosmaer (1885, p. 363), and this 

 might be retained as a separate genus, though the affinities are so 

 close this seems to me inadvisable. Our Californian form is very 

 close to fragilis^ but differs in rather smaller fiber, which is also 

 more sparsely cored, and by the frequency with which the principal 

 fibers are horizontal as well as vertical. 



Family VERONGIIDAE ^ 

 Genus VERONGIA Bowerbank 



VERONGIA THIONA de Laubenfels 



Verongm thiona de Laubenfels, 1930, p. 28. 



Holotype.—V.S.^M. No. 21500; B.M. No. 29.8.22.31. 



Type locality. — Laguna Beach, Calif., intertidal, March 14, 1926, 

 abundant. 



Description. — Shape, encrusting. Size, up to 4 cm thick, 12 cm in 

 diameter. Consistency, spongy. Color in life, lemon yellow with 

 greenish tints; in alcohol very dark purple. Oscules, few and scat- 

 tered; diameter 2 to 7 mm. Pores, not evident, evidently very con- 

 tractile. Surface, superficially smooth with conules 0.5 mm high, 

 irregularly scattered. 



Ectosomal specialization, a cellular dermis about T/x thick. Endo- 

 somal structure, as typical for this genus, of the general consistency 

 of a rather stiff jelly, permeated by meandering canals (about 1 mm 

 in diameter) and by rather scattered fibers in reticulation. These 

 fibers are clear yellow, with a core often apparently empty, again 

 filled with opaque substance. In this species the thickness of the 

 peripheral portion seems much more constant than the size of the 

 pith, which is larger in the larger fibers, smaller in the smaller. The 

 mesh is so very irregular in outline that it is very difficult to assign it 

 measurements, but one is safe in saying that the mesh size averages 

 more than 1 mm. 



Histological details : The flagellate chambers are spheroidal, 25|Li in 

 diameter. Principal fibers 80/x to 150/Ain diameter, cored by the usual 

 pith as found in this genus. Pith of the fibers, 50/x to 110/^ in diam- 

 eter. (Fig. 77.) 



* For Aplysinidae Schuize, because Verongia supplants Aplysina 



