THE SPONGES OF THE WEST-CENTRAL PACIFIC 43 



The vast majority of these objects dissolve in boiling nitric acid, yet with 

 little or no carbon dioxide gas formed. They are, therefore, almost certainly 

 neither silica nor calcium carbonate. It is possible that they are chemically 

 the fluoride of some one of the less common metals. It is furthermore pos- 

 sible (although far from certain) that they are actually produced by the 

 sponge in which they are found. Their diameter is usually 4 fi, rarely as little 

 as 3 ju, or as great as 5 /x. They seem always to be broken and pieces as long as 

 500 /x are uncommon. No sharp pointed termination, or other indication of 

 unbroken ends, could be found. 



This species was described first by de Laubenfels, 1936, page 28, from 

 the West Indies (Dry Tortugas). It is very abundant in the Bermudas, 

 but this is the first record from the Pacific area. 



GENUS EURYSPONGIA Row 

 Euryspongia phlogera, new 



Text Figure No. 23 



This species is here represented by the following : 

 U.S.N.M. No. 22952, My No. M. 326, here designated as type, collected on 

 June 24, 1949, by diver at Ailing-lap-lap Atoll at the east end of the 

 lagoon, near Jih Islet. The depth was 12 meters, and the substrate was 

 dead coral. 



This is a massive or club-shaped specimen, 15 cm high and 6 cm in 

 diameter. 



The exterior and interior color in life was a vivid reddish orange. The 

 consistency was softly spongy. 



The surface is conulose, with conules about 2 or 3 mm high and 8 to 10 

 mm apart. Each shows a protruding fiber, and many of these fibers are 

 somewhat branched at the distal termination. The pores are about 300 n in 

 diameter and are abundant, about one for each square mm. Each of these 

 skeletal pores, however, is in turn filled in with a protoplasmic membrane, 

 which is perforated by holes about 45 p. to 75 p in diameter, the partitions 

 between which are only about 5 p wide. This strongly suggests the genus 



Text Figure No. 23. Portion of 

 the fiber of Euryspongia phlo- 

 gera, X 182. The conspicuous 

 core of foreign material is 

 illustrated. 



