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PEOCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 81 



Principal spicules, styles (fig. 32, A) ; size, about 20)u, by 1,300/a. 

 First microscleres, sigmas (fig. 32, .5) ; size, about 13/^ by 300/x. Sec- 

 ond microscleres, sigmas (fig. 32, C) ; size, about 4/^ by 90ju,. Third 

 microscleres, sigmas (fig. 32, Z>) ; size, about 1/x by 25/x. Fourth 

 microscleres, smooth raphides (not figured) ; size, Ifi by 120ja to 2/x 

 by 210jx', these are usually packed in short fascicular tracts about 

 50/A in diameter. 



Remarks. — The nearest relative of this form seems to be B. {Des- 

 macella) fortis Topsent, 1897, from the East Indies and Red Sea, 

 which differs in not having the larger size range of sigmas. Biemna 

 megalosigina Hentschel, 1912, has the large size range of sigmas as 

 well as the medium and smaller, but has peculiar siliceous spheres 



FiGDRB 32. — Biemna rhadia de Laubenfels, X300. A, termina- 

 tions of the styles, showing their thickness but not their 

 length ; B-D, range in size and shape of the sigmas 



not in the California species, has megascleres but two-thirds as large, 

 and raphides also much smaller. It may well be that upon making 

 thorough revision of the genus one would find these and numerous 

 other species of Biemna worthy of reduction to synonymy, but this 

 step does not seem called for at present. 



Similar species of this genus are reported from practically all 

 parts of the world. 



Genus DESMACELLA Schmidt 



DESMACELLA VAGABUNDA Schmidt 



Desmacella vagabunda O. Schmidt, 1870, p. 53. 



Holotype. — ^Location unknown ; described from the West Indies. 



Material examdne'd. — One of several specimens (U.S.N.M. No. 

 21508; B.M. No. 29.8.22.61) growing in the interstices of a macerated 

 dictyonine hexactinellid sponge skeleton collected by E. F. Ricketts, 

 May 9, 1929, in Monterey Bay, depth 700 meters. 



