THE SPONGES OF THE WEST-CENTRAL PACIFIC 241 



sponge. The pores are arranged in poral calyces, which are each about 4 by 

 7 mm in dimensions and about 5 mm deep. These are arranged in a row, 

 which usually makes an equatorial belt around the sponge at its widest dia- 

 meter. The oscules are very contractile and difficult to locate, being situated 

 usually about the middle of the top of the sponge. The ectosome is a muscular 

 cortex, nearly 1 mm thick. The endosome is pronouncedly radiate in structure. 



The skeleton comprises oxeas up to 50 [x thick and at least 8 or 9 mm 

 long. In some specimens, they reach only to a somewhat smaller size but are 

 still relatively enormous. There are also anatriaenes, consistently present, 

 with clads about 5 [x by 100 \x and rhabds about 5 ju, by 1500 [x. In No. M. 219, 

 a few prodiaenes were found with clads 4 [x by 125 //,, and rhabds, about 6 \x 

 by perhaps 1 mm in length. The microscleres are strongly contorted sigma- 

 spires which are about 2 fi thick and 8 fi to 12 /x in chord length. If straight- 

 ened out, this spicule would be approximately 20 \x to 25 //, long. The spination 

 on it is very fine indeed, requiring oil immersion for clear observation. 



Lendenfeld in 1888, page 43, established a species which he called 

 Spiretta porosa for Australian sponges. This was put into Cinachyra, proper- 

 ly, by Burton, 1934, page 526. 



Cinachyra australiensis (Carter) Burton 



Text Figure No. 166 



This species is here represented by the following: 



U.S.N.M. No. 23039, My No. M. 418, collected July 30, 1949, by diver in 

 northwest Ponape in the lagoon near the shore. The depth was 3 meters, 

 and the substrate was dead coral fragments. This species was common in 

 Ponape. 



U.S.N.M. No. 22903, My No. M. 207, collected August 13, 1949, by diver 

 in the west part of Truk Lagoon at Lemotol Bay. The depth was 4 

 meters, and the substrate was coral sand. This species was also common 

 in Truk. 



U.S.N.M. No. 22814, My No. N. 020, collected March 7, 1946, by J. P. E. 

 Morrison at Bikini Atoll under rocks in low intertidal zone near Bikini 

 Islet. This sponge is identified with grave doubts. Its microscleres are 

 very small, only about 6 \x in chord length, and, therefore, it may be that 

 it should be put in a new species. 



T. E. Bullock in 1948 collected at Bikini Atoll at least two sponges which 

 are conspecific with the preceding and thus dubiously here classified as 

 Cinachyra australiensis. Their microscleres were only 5 /x in chord length. 



Cinachyra australiensis, like most others in this genus, is subspherical, 

 about 3 to 6 cm thick and 4 to 8 cm in diameter. 



The color in life was dirty yellow externally and bright yellow internally. 

 The consistency was mediocre to cartilaginous. 



