484 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



These connectives are much like many of the connectives o\ 

 Euspongia officinalis, but the almost complete absence of the branch- 

 ing' and anastomosing habit gives them a strikingly independent 

 appearance, and the way in which they are secondarily united by 

 synapticula and amorphous little masses of spongin is very peculiar. 

 They seem at bottom to be ordinary spongin fibers and quite dif- 

 ferent things from Hircinia filaments, a resemblance to which may 

 possibly be suggested by the mere verbal description. 



I find that slender cylindrical connectives with a narrow medul- 

 lary streak, in general quite similar to the connectives of P. aliena, 

 occur here and there as constituents of the skeletal network in my 

 preparations of P. foliascens, and are in places united by spongin 

 synapticula quite as in P. aliena. Further, they are distinguishable 

 in many parts of the skeletal network of this species {foliascens) 

 as axial cores round which stratified spongin has been deposited. 

 In fact, I suspect that the skeletal reticulum of P. foliascens is built 

 up very largely on a primary foundation of cylindrical connectives 

 like those of P. aliena. 



Holotype.— €at. No. 21288, U.S.N.M. 



Genus EUSPONGIA Bronn (1859). 



Euspongia Bronn, 1859. — Lendenfelp, 1889, pp. 222-223 (synonymy in 

 detail). 

 Skeletal network pretty evenly developed throughout the often 

 massive, but also vasiform, lobose, digitately branched, or lamellate 

 body ; all fibers, slender ; meshes very small, not or scarcely percep- 

 tible to the eye. Main fibers simple, terminating, as a rule, singly in 

 the conuli, but the main fiber may break up into two or three branches 

 all of which terminate in one conulus; main fibers with inclusions; 

 connecting fibers uniformly cylindrical, without inclusions, branching 

 and continually anastomosing. 



EUSPONGIA OFFICINALIS (Linnaeus). 



Spongia officinalis Linnaeus, 1735. 



Euspongia officinalis Lk.ndenfeld, 1889, p. 262 (synonymy in detail). 



The collection includes 15 cut pieces all taken on same day, August 

 26, at Hinitungan, and representing a number of sponges, all massive 

 and 80-180 mm. in diameter. They are all alike. The conuli are 

 sharp, about 1 mm. high and 1.5-2 mm. apart, commonly connected 

 by ridges, the intervening areas depressed in the usual way. The 

 radial skeletal fibers frequently protrude at the conuli, singly or 

 two or three in one conulus. A number of oscula, 4-9 mm. in 

 diameter, on upper part of sponge. Surface blackish, lighter in 

 lower part of sponge ; interior yellowish brown to reddish. Several 

 of the sponges with eggs. 



