128 U.S. NATIONAL MUSEUM BULLETIN 2 72 



groups. However, he too failed to see the intimate relationship of 

 those "heterogeneous" species with stellate microscleres, which he 

 grouped into the new subgenus Astroheteromeyenia, to the "homoge- 

 neous" group represented by Dosilia. 



Since the definition of Dosilia Gray, as here amended, makes it 

 possible to include aU known species with stellate microscleres into 

 this genus, no apparent purpose can be served by severing their 

 obvious natural relationships with their relegation to two different 

 genera. Moreover, the transfer of the two heterogeneous species of 

 Dosilia to Heteromeyenia is now impossible, since the latter genus has 

 been restricted in this paper for the inclusion of those species with 

 heterogeneous gemmoscleres which possess diactine microscleres. 

 Both H. radiospiculata Mills and H. plumosa Weltner are therefore 

 herewith included in Dosilia, an arrangement that will make it neces- 

 sary to rename Weltner's species, should this eventually not be found 

 identical with H. radiospiculata as assumed by the present authors. 



Dosilia plumosa (Carter, 1849) 



Plate 11, figures 2-5 



Spongilla plumosa Carter, 1849, p. 85. — Bowerbank, 1863, p. 449. 



Dosilia plumosa Gray, 1867, p. 551. — Annandale, 1911c, p. Ill; 1912d, p. 384; 



1918a, p. 213.— Gee, 1932c, p. 28; 1932f, p. 529.— De Laubenfels, 1936, 



p. 37.— Jewell, 1952, p. 450.— Penney, 1960, p. 39. 

 Meyenia plumosa Carter, 1881a, p. 94. — Potts, 1887, p. 233. 

 Ephydatia plumosa Weltner, 1895, p. 126. 

 (Not Heteromeyenia plumosa Weltner, 1895.) 



Materl^l. — Slides of type (BM and IM); specimens and slides 

 from India (N. Gist Gee). 



Description. — Sponge, according to previous authors, massive 

 and bulbous; siu-face uneven, lobose, oscula small but conspicuous, 

 dermal membrane well developed. Skeleton consisting of well-defined 

 radial spicule fibers, coated together by a varying amount of spongin, 

 and much slimmer transverse fibers. Consistency moderately soft 

 but very fragile. 



Megascleres slightly curved, distinctly fusiform, and smooth am- 

 phioxea; length range 400-520 n, width range 15-21 n. 



Microscleres present in great abundance in the symplasm and the 

 vicinity of gemmules; they are stellate spicules consisting of 8-12 

 rays projecting from a distinct central globular nodule; the rays usually 

 smooth, terminating in a small number of minute recurved distal 

 spines; occasionally the microscleres are represented by granulated 

 amphioxea which bear in their central portion a number of radiating 

 and perpendicular rays; length range of microscleres extremely 

 variable, radius of rays not exceeding 15-18 /z. 



