232 



THE SPONGES OF THE WEST-CENTRAL PACIFIC 



3"- 



^1 



Y 



* 



D 



Text Figure No. 159. Spicules of Tethya viridis. A: Strongyle, X 182. B: Spheraster, 

 X 782. C: Chiaster, X 782. D: Euaster, X 782. 



The ectosome consists of a cortex, 1.5 mm thick. The endosome is fleshy 

 and strongly radiate, with tracts of spicules. 



The megascleres are strongyloxeas, as typical of the genus Tethya, 

 dimensions about 13 jx by 1100 [x. The microscleres include, first of all, large 

 spherasters with coarse spines. They are about 5 /x in diameter and have very 

 numerous rays. The others, about 7 /x in diameter, have only about 10 to 15 

 rays. These latter seem to be chiasters. 



This species was first described as Donatia viridis by Baer, 1905, page 26, 

 from the southwest Pacific. All efforts to determine its world distribution are 

 confused by the fact that various authors, quite understandably, find difficulty 

 in separating viridis from diploderma. The two may indeed be conspecific, 

 but viridis more often is green or black on the exterior. 



Tethya diploderma, Schmidt 



Text Figure No. 160 



This species is here represented by the following: 

 U.S.N.M. No. 22862, My No. M. 156, collected July 11, 1949, by diver near 



the south corner of the lagoon near the church at Likiep Atoll. The depth 



was 3 meters, and the substrate was dead coral. 

 U.S.N.M. No. 22865, My No. M. 159, collected July 11, 1949, at the same 



locality as the previous specimen. 

 U.S.N.M. No. 22872, My No. M. 167, collected July 13, 1949, by diver near 



the south side of the lagoon near Eotli Islet at Likiep Atoll. The depth 



was 5 meters, and the substrate was dead coral. It was found inside a 



large cavity of the coral, to which there was an exceedingly small 



entrance. 



