66 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.81 



Descin/ption. — Shape, encrusting. Size, 1 to 3 mm thick, spread- 

 ing laterally indefinitely. Consistency, soft, fleshy. Color in life, 

 pale ochraceous-yellow. Surface, lipostomous and smooth. A con- 

 spicuous feature of the living and preserved sponge is the very 

 evident system of comparatively coarse canals meandering about 

 beneath the transparent dermis, branching and reuniting. It is to 

 be presumed that contractile minute exhalent apertures riddled the 

 covering to these canals during life, and that similar inhalent open- 

 ings were dispersed over the rest of the surface. 



Ectosomal specialization, fleshy, abundantly packed with micro- 

 scleres. Endosomal structure, basically fleshy with abundant 

 microscleres and scattered ascending plumose tracts of tylostyles, 

 points upward and out- 

 ward. These make incon- 

 spicuous terminal brushess 

 at the places where the 

 tracts reach the surface. 

 The^e tracts are approxi- 

 mately 50/A apart ; they 



Figure 34.— Zj/gr/ierpc hyaloderma, new species : branch and anastomoSe 

 A-E, X300; F-H, X 600 i , i 



but rarely. 



Megascleres, tylostyles about 5fi by 150/*, First microscleres, 

 sigmas 25/a to 50/x, in length of chord. Second microscleres, dian- 

 cistras, the points nearly meeting. 



Remarks. — The diancistra is a very curious and characteristic 

 spicule. Possession thereof can hardly be used, however, as an 

 indication of close phylogenetic relationship, for the three previousl}' 

 described genera having this microsclere differ fully as much from 

 each other as from Zygherpe. In addition to the diancistra, each 

 possesses other spicules as follows : Hamacantha, styles to oxea 

 and toxas with rhaphides; Vo77K37nda, styles and toxas with chelas; 

 Pozziella, exotyles, peculiar styles and very peculiar sigmas. As 

 mentioned above, Zygherpe seems much more closely related to 

 Desmacella than to any other genus. 



Genus MYCALE J. E. Gray 



MYCALE BELLABELLENSIS (Lambc) 



Esperella bellabellensis Lambe, 1905, p. 14. 

 Esperella fisheri de Laubenfels 1926, p. 570. 



Holotype. — In the Museum of the Geological Survey. Ottawa, 

 Canada. 



Type locality. — The west coast of Canada. 



Material examined. — There is a magnificent specimen of this 

 sponge at Hopkins Marine Station (Pacific Grove) a good 4 feet 



