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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL, 81 



As for the relationships of this species, I may quote my 1927 

 article (p. 2G3), as follows: 



Its closest relatives are P. manaarensis Carter, ISSO, from India, and P. novi- 

 selanica Ridley 1881, from New Zealand. Both of these, however, are Oorgonia- 

 like in architecture, the former has an isodictyal structure, the latter has its 

 tylotes entirely spined and both have very large smooth styles quite unlike any 

 in our local fonn. 



There is in the United States National Museum a small fragment of a sponge 

 with no more definite locality record than from " The Coast of California," 

 which Mr. L. M. Lambe identified as P. manaarensis. It certainly is not the 

 Indian sponge, but there is not enough of it to be sure if it is P. karyMnos or 

 some other Plocamia. 



PLOCAMIA IGZO, new species 



Holotype.—V.S.^M. No. 22058; B.M. 30.10.8.1. 



Type lo'cality. — Collected by me at Point Pinos, Calif., intertidal, 

 July 11, 1930. 



Descriptio7i. — Shape, encrusting. Size, 9 mm thick. Consistency, 

 stiff to fragile. Color in life, carmine-red. Oscules, not evident. 

 Pores, very evident ; 20ju, to 25jli in diameter and only about 70/a to 75/i, 

 apart, center to center. The surface was minutely hispid, very 



lumpy. 



Ectosomal specialization, a very intangible protoplasmic dermis, 

 not separable ; it contains abundant microscleres. Endosomal struc- 

 ture : There are rather 

 meandering but in gen- 

 eral ascending plumose 

 tracts, containing per- 

 haps a little spongin. 

 The total diameter of 

 each is about 200jli, 

 and each is profusely 

 echinated by smooth 

 monaxons. 



There are regions 

 where the flesh contains 

 practically no spicules 

 except the microscleres. Principal spicules, tylostyles with heads 

 often but apparently not always spined, the spines varying from 

 coarse to exceedingly fine (fig. 61, A-C) ; the common range is from 

 11/x, by 190/x to 35|it by 2'lOjii. Some very thin ones are probably imma- 

 ture or undeveloped examples of this spicule sort. These spicules 

 make up the bulk of the megascleres; namely, the plumose columns. 

 Secondary spicules, tylotes, with heads varying from rather coarsely 

 spined to very finely so, or not at all (fig. 61, D-F) ; the size range is 

 commonly about 13/x by 130/a, but there are much thinner ones, pre- 



FiGDRE 61. — Plocamia igzo, new species, X300, except 

 n, X 2,400 



