SILICIOUS AND HORNY SPONGES WILSON. 487 



interior of sponge. Connectives and skeletal net show the irregu- 

 larities (as compared with E. officinalis) characteristic of the species. 

 Connectives in general 28 y. thick, but smaller ones also abundant, 

 varying down to 10 y. thick; distribution of latter varies a good deal, 

 however, for in some parts of a section all of the fibers are of about 

 one thickness, 28 y. The finer connectives are pretty well marked off 

 from the larger, extending between the latter and subdividing the 

 spaces embraced by them. These spaces vary from polygonal meshes 

 as definitely bounded as in E. officinalis to elongated spaces which 

 often are indefinitely bounded at one end. Typical meshes embraced 

 by the larger fibers have the following dimensions : 700 by 250 [/., 420 

 by 245 [jl, 350 by 280 y., 350 by 350 jji, 280 by 210 jx, 210 by 77 [x. The 

 smaller meshes produced by the finer connectives range down to 70 \x 

 wide. 



Holotype.— Cat, No. 21263, U. S. N. M. 



In the possession of slender, cylindrical cloaca! tubes (fistulae) the 

 Albatross sponge agrees with E. irregularis, var. fistulosa, from the 

 Bahamas (Lendenfeld, 1889, p. 249), but these are massive more or 

 less spherical sponges, which in other respects also are not especially 

 close to the Albatross form. In its branching habit, also in the pos- 

 session of aconulous areas and small oscula, the latter resembles var. 

 jacksoniana from Australian waters (Lendenfeld, 1889, p. 254). But 

 in var. jacksoniana there are no cloacal tubes, and the main fibers are 

 100 [/. thick with a dense axial column of large sand grains. Another 

 branching Euspongia is E. tenuiramosa from Ceylon (Dendy, 1905, 

 p. 213), but without other special resemblances to var. suriganensis. 

 It is plain that a practically infinite number of combinations of char- 

 acters is possible, and may in fact now exist, in these sponges, owing 

 to the independent variability of features. The new varietal name is 

 given to the form simply that the combination which it represents 

 may not be lost sight of. 



Lendenfeld (1889) gives the distribution of the species. Topsent 

 (1897, p. 484) has since recorded it for Amboina, and Hentschel 

 (1912, p. 435) for the Am Islands. 



Subfamily Aplysininae. 



Aplyxlninac Lendenfeld, 1889, p. 335 plus PsommaplysUUdCbe Keller, 1889, 

 p. 358. 



Skeletal fibers contain a conspicuous axial pith or, more rarely, 

 are composed entirely of pith substance. 



Genus PSAMMAPLYSILLA Keller (1889). 



Psammaplysilla Kellkk, 1889, p. 358, pi. 22, fijrs. 28-27. 



Fibers consisting of a minutely reticulate pith substance, which 

 is sometimes imperfectly surrounded by a very thin development 



