244 ART. 7. 1. IJIMA : HEXACTINELLIDA, IV. 



sometimes fringe the oscular margin, were not observed on the 

 lateral wall of the larger specimens. 



The subdermal space is narrow. The variously sized apertures 

 of incurrent canals, visible through the ectosome, may be as large 

 as 5 mm. in diameter (PI. XVIIL, fig. 2). The interapertural 

 choanosomal surface, usually not wider tlian the width of the 

 directly adjacent canalar apertures, shows an interweaving of fibers 

 or strands which run irregularly but in tlie main in oblique 

 directions. In the proximity of the basal attachment the 

 parenchymal texture is dense and coarsely fibrous. 



On the inner side of the wall, the endosome show^s a con- 

 tinuous gastral lacework (PI. XVIIL, hg. 3) the quadrate meshes 

 of which are distinctly visible to the naked eye. The gastral 

 layer is supported below by a w^ell differentiated system of hypo- 

 gastral strands which are long and of various strengths under 

 oOO n and which by intersecting one another enclose wide meshes 

 of an irregularly angulate shape. Frequently the strands are seen 

 to run over and across the apertures of the excurrent canals. 

 Interaperturally the endosome is closely adherent to the choano- 

 some. 



The excurrent canalar apertures are of about the same size 

 as the incurrent on the external side, but are somewhat more 

 closely set together. Both the incurrent and excurrent canals 

 are pit-like ; when seen in sections of the body-wall, they are 

 alternately arranged, their wall showing variously sized, oval or 

 roundish entrances into the branches. 



Finally, a few words with regard to the small and young 

 specimens of the species. The smallest I have seen was only 23 

 mm. high, thin- walled and with an osculuni of 3 mm. diameter 



