l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



Family LATRUNCULIIDAE Topsent 

 ALCYOSPONGIA, n. gen. 



This genus is proposed for a specimen bearing some apparent re- 

 lationship to the genus Podospongia du Bocage which is usually placed 

 in the family Latrunculiidae. The West Indian specimen, however, 

 has straight streptasters not conspicuously symmetrical as are those 

 of Podospongia, and a slight but perhaps significant difference in 

 architecture in that the central point to the radiate structure of the 

 mass of the sponge is basal, that is, near the pedestal, rather than cen- 

 trally located within the spherical main portion. Consequently the 

 family allocation must be regarded as dubious. The diagnosis of Alcyo- 

 spongia may be given as sponges with stalk and root, radiate structure 

 in the main mass, spiculation of oxeas to which straight streptasters 

 are added, the latter frequently showing nodal arrangement of spines. 



Genotype and only species. — Alcyospongia india, new species. 



ALCYOSPONGIA INDIA, n. sp. 



Holotype. — U.S.N.M. no. 22365. 



The one specimen and some doubtful fragments were collected at 

 station 81, latitude i8°29'45" N., longitude 6s°25'5o" W. to latitude 

 i8°35'3o" N., longitude 65°23'54" W., February 26, 1933, 200 to 400 

 fathoms. 



This sponge has its main body not quite spherical, about 10 mm 

 in diameter. The stalk is i mm in diameter and attains a total length 

 of 20 mm. At the lower end it divides first once dichotomously, and 

 then each branch divides into several fine rootlike structures. The 

 color as preserved in alcohol is very pale, nearly white. The consis- 

 tency is softly spongy. The surface is even, and there is no easily 

 detachable ectosome. The pores are abundant, easily seen with the 

 unaided eye, about i mm apart ; no especially large ones could be made 

 out, and the exhalant apertures are therefore unknown. The archi- 

 tecture is in general radiate, and is described under the foregoing 

 generic diagnosis. The fibers, which spread out into the head of the 

 sponge from the stalk, are each about 140 ju, in diameter. The princi- 

 pal spicules are oxeas, about 10 /a by 500 /^ in dimensions, but so fre- 

 quently broken that the maximum sizes cannot be given with certainty. 

 The microscleres show considerable variation. Some of the simpler 

 ones are scarcely more than acanthoxea, or spiny rhabds, about 40 ju, 

 to 50 /A long, with spines about 3 /a to 5 /x, high. There is a pronounced 

 tendency, however, for the spines to be grouped in two nodes along 



