ART. 4 



SPONGES OF CALIFORNIA db LAUBENFELS 



101 



Family PLOCAMrilDAE Topsent 

 Genus PLOCAMIA O. Schmidt 



PLOCAMIA KARYKINA de Laubenfels 



Plocamia karykinos de Laubenfels 1927, p. 262. "■ 



HoIoti/pe.—V.S.^M. No. 21480; B.M. No. 29.8.22.35. 



Type locality. — Pacific Grove, Calif., intertidal, July, 1925. The 

 species is very abundant in central California but seems lacking in 

 the southern part of the State. 



Description. — Shape, encrusting. Size, up to 4 cm thick, spread- 

 ing laterally indefinitel3^ The thickness is usually well under 1 cm. 

 Consistency, firm, woody. Color in life, brilliant scarlet; preserved, 

 drab. Oscules, sometimes with slightly raised collars; diameter 1 

 to 2 mm; about one to the square centimeter. Pores about 180ft in 

 diameter when fully 



open; about one to the ~" ^===> ^ 



square millimeter. Sur- 

 face, superficially his- 

 pid; level. 



Ectosomal specializa- 

 tion, vague or lacking. 

 The tylostyles classed 

 as interstitial are also 

 found rather frequently 

 at the surface. Endo- 

 somal structure, plu- 

 mose ascending col- 

 umns with ladderlike 

 connectives. A s c end- 

 ing fibers, 50/t to lOO/i, 

 in diameter, cored by 

 subtylostyles. Accessory or transverse fibers consisting of single 

 spicules only, the tylotes. 



Principal spicules, subtylostyles with microspined heads (fig. 

 60, ^) ; size, 18/i by 175/a to 22)u, by 220 fi. Secondary spicules, tylotes 

 with microspined heads (fig. 60, O) ; size, 16/a by 210/a to 22/a by 175/a. 

 Interstitial spicules, tylostyles (fig. 60, J.) ; size, 2/* by 200/a to dfx by 

 160/x; besides occurring interstitially these are almost common enough 

 at the surface to be considered also as ectosomal. First microscleres, 

 palmate isochelas (fig. 60, E, F) ; length, lOyu, to l7/x. Second micro- 

 scleres, toxas (fig. 60, D) ; length, 18/x to 80/i. 



Remarks. — This species has a characteristic useful in field de- 

 termination — upon injury, it emits copious quantities of a colorless 

 slime not conspicuous before the injury. 



Cf=Q E'^^ 



^=^ ^C)=0 



Figure 60. — Plocamia karykina de Laubenfels : Two 

 spicules {P), X 1,333; others, X300 



