THE SPONGES OF THE WEST-CENTRAL PACIFIC 77 



and occasionally are also encased in a thin film of spongin. Instead of tri- 

 angular or square or diamond-shaped meshes, as is so often true in the genus 

 Haliclona, the meshes in this case are often polygonal in outline and as much 

 as 200 /x in diameter, so that the skeleton makes up only a small fraction 

 of the mass of the organism. 



This species was common at Ailing-lap-lap, but was not collected, because 

 of the extreme extent to which it did not resemble a sponge. It was assumed 

 to be a mass of mollusk eggs. It was again found commonly at Ebon, and 

 just before leaving there I collected a bit, merely out of curiosity. Sections 

 revealed the reticulation of spicules and the flagellate chambers. 



Other species and genera of sponges contain similar mucoid material, 

 but it is doubtful that any other possesses such large quantities. The pale 

 threads constitute an even more unique and puzzling addition. Each speci- 

 men of this sort that I observed was full of them, and I did not find any- 

 thing like them except in sponges of this sort. When put through histologic 

 technique, they refused to take hematoxylin, but did stain vigorously with 

 safranin, as though they were made of lignin. They show no trace of cellular 

 or other organization and are comparatively solid and amorphous. They 

 are certainly not ordinary spongin but might be chemically related to spongin. 

 On the other hand, they do not look like spongin fibers and do not branch 

 as spongin fibers regularly do but lie in undulating semi-parallel arrange- 

 ment. Are they foreign inclusions or manufactured by the sponge? Are 

 they a result of the copious slime production, or a cause of it? 



The species name is from the Greek for "containing threads." 



GENUS CRIBROCHALINA Schmidt 

 Cribrochalina olemda, new 



Text Figure No. 47 

 Plate IV, Figure a 



This species is here represented by the following : 

 U.S.N.M. No. 23115, My No. M. 497, here designated as type, collected 



September 2, 1949, by divers in Komebail lagoon, northwest of Koror in 



the Palaus. The depth was 5 meters, and the substrate was dead coral. 

 U.S.N.M. No. 23077, My No. M. 459, collected August 13, 1949, by diver 



in the west portion of Truk lagoon, south of Polle Islet. The depth 



was 4 meters, and the substrate was dead coral. 



This species was uncommon at Truk, much more conspicuous in the 



Palaus. 



The shape is tubular, little if any larger in diameter at the top than at 

 the point of attachment. Occasionally two such tubes touch and anastomose. 

 Very rarely one finds a specimen in which there is a branch. Such a branch 

 is apt to be nearly at right angles to the original stem. The total diameter is 



