AET. 4 



SPONGES OF CALIFORNIA de LulUBENFELS 



105 



Color in life, brilliant scarlet; preserved, drab. Oscules, round, 

 often with elevated, craterlike rims; diameter about 4 mm; distance 

 apart 2 to 5 cm. Pores, abundant, minute, represented by the spaces 

 between the distal ends of the ascending columns. Surface, super- 

 ficially hispid. 



Ectosomal specialization : There is an occasional patch of a very 

 thin dermal membrane covering the larger spaces between the sum- 

 mits of the columns. Endosomal structure, characterized by con- 

 spicuous ascending tracts. Histological details: The flagellate 

 chambers are subsplierical and about 30/x to 40/x in diameter. Ascend- 

 ing fibers, 200ju, to 350/^ in diameter, nearly 1 mm apart. 



FiGDKB 63. — Acarnus erithacus de Laubenfels : I-K, X 1,333 ; others, X300. E, D, 

 uncommon intermediates between C and F 



Ectosomal spicules, tylotes with heads microspined (fig. 63, B) \ 

 size, 2>fi by 185/x to 4ju, by 175/.1. Interstitial spicules, cladotylotes 

 (fig. 63, C) ; size, 11/x by 230/x, chords 35/i,. Coring spicules, styles 

 (fig. 63, J.) ; size, ISjti by 345^i to 17/a by 425/x; these are the most con- 

 spicuous spicular element. Echinating spicules, acanthocladotylotes 

 (fig. 63, F) ; size, 3ju, by 80/t, chords 11/i, and larger. First micro- 

 scleres, palmate isochelas (fig. 63, (?, I-K) ; length, 14;u, to 16/i. 

 Second microscleres, toxas (fig. 63, H) ; length, 40/x to 340/x. 



ReTnarks. — Tlie most conspicuous spicules are the smooth styles, 

 which are grouped, points toward the surface, in ascending plumose 

 tracts held together by a small quantity of nearly invisible spongin. 



