206 



THE SPONGES OF THE WEST-CENTRAL PACIFIC 



Text Figure No. 139. Spicules of Aaptos unispiailus, X 182. A: Style with swollen 

 shaft. B: Very thin oxea, or raphide. 



The color in life was pink, and the consistency was hard. 



The surface is level and lipostomous. 



The ectosome consists of a dense stand of spicules, and the endosome 

 mostly of spicules chiefly in confusion. 



The skeleton consists of styles with considerably enlarged central por- 

 tion, ranging up to as much as 18 /j. by 800 jx in the specimen from the Mar- 

 shall Islands. 



This species was first described as Hymeraphia unispiculum by Carter, 

 1880, page 467, from the Indian Ocean. It was transferred to Aaptos by 

 de Laubenfels, 1936, page 152. 



Aaptos chromis, new 



Text Figure No. 140 



This species is here represented by the following : 

 U.S.N.M. No. 23086, My No. M. 468, here designated as type, collected 

 August 13, 1949, by diver in Lemotol Bay in the western portion of Truk 

 lagoon. The depth was 4 meters, and the substrate was dead coral. 



This species is massive, 10 cm high, and 10 by 20 cm in horizontal 

 measurement. 



The color in life was dull green to dull dark drab on the exterior but 

 always brilliant yellow on the interior. The appearance of the outside must 

 be considered further in connection with the discussion of the ectosome. The 

 consistency was spongy, but the spicules could be felt sensibly by the finger- 

 tips. 



The surface is densely hispid, like velvet or fine plush. In this structure, 

 the pores, being closed, cannot be made out, but the oscules are quite notice- 

 able, 8 mm in diameter and 3 to 6 cm apart. The oscules in this species are 

 closed in a powerful and fairly rapid manner by muscular contraction, like 

 sphincters. 



In addition to containing many spicules erect with points toward the 

 outside, the ectosome is covered with symmetrical patches of debris. Pores 



B 



Text Figure No. 140. Spicules of Aaptos chromis, X 182. A: Style. B: Raphide. 



