14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



The diameter of each is about 5 ./x, and the length, if straightened out, 

 would be nearly 300 fi. 



As noted above, there is some slight indication of relationship in 

 general to the genus Acanthella, but no one species of sponge appears 

 to be closely related to Viles ophiraphidites. 



DENSA, n. gen. 



This genus is established for a sponge that shows very close relation- 

 ship to the genus Hymeniacidon Bowerbank in every respect, includ- 

 ing the arrangement of the spicules and the endosome and ectosome, 

 except that as spicules there are oxeas only, and not styles as charac- 

 teristic of Hymeniacidon. Further comparison might be made to the 

 genus Collocalypta Dendy, which reads on paper as if it might be 

 closely related, but it is sharply separated by having a notable quantity 

 of spongin and even more colloidal jelly conspicuously present. The 

 genus Hoplochalina Lendenfeld resembles Densa in some respects, 

 but is notably fibro-reticulate in architecture. Halichondria Fleming 

 itself deserves comparison here, but it is a genus not nearly so dense 

 and possesses a conspicuous detachable dermis. As noted above, the 

 evidence would seem to be of closest relationship with Hymeniacidon. 



Genotype. — Densa araminta, new species. 



DENSA ARAMINTA, n. sp. 



Holotype. — U.S.N.M. no. 22298; from station 26, latitude i8°3o' 

 20" N., longitude 66°22'o5" W. to latitude i8°3o'3o" N., longitude 

 66°23'o5" W., February 7, 1933, 33 to 40 fathoms. 



The specimen is an irregularly lobate mass, 3 by 5 hy 8 cm. The 

 color is greenish black as to exterior, over a pale drab interior. The 

 consistency is somewhat compressible, easily torn, and might be de- 

 scribed as mediocre. The surface is microtuberculate, optically even, 

 being well rounded over the protrusions. The dermis is not easily 

 detachable, being a confused mass of spicules blending into the con- 

 fused breadlike cavernous interior. The oscules and pores could not 

 be made out. The spiculation consists exclusively of oxeas, of which 

 typical sizes may be listed as follows: 4 /a by 100 /a, 5 /a by 140 /*, 

 3 ^ by 90 II. 



Sponges having such simple spiculation may appear in print as 

 though closely related, but actually they may be quite distinct geneti- 

 cally. There are many species in several genera which on paper bear 

 some resemblance to D. araminta, but in view of the information at 

 present available close relationships cannot be established. 



