THE SPONGES OF THE WEST-CENTRAL PACIFIC 87 



of 15 cm or more, and some in Guam were over 40 cm. The diameter of the 

 branches is 1 to 3 cm, but this varies greatly from place to place, as the struc- 

 ture is decidedly lumpy. The branches are often tangled, and frequently 

 anastomose. 



The color in life was very much the same as between endosome and ecto- 

 some, but had some very peculiar characteristics. It was basically a pale blue 

 with many brown patches ; or, in the case of those from Guam, it was rather 

 a gray with orange patches. These patches blended into each other and were 

 found both on the upper or brightly illuminated portions and on the lower 

 more shaded portions. Many sponges show drab regions which are evi- 

 dently the result of pathological or moribund conditions, but these brownish 

 patches, in the species under discussion, appeared to be quite healthy. The 

 consistency was spongy. 



The surface varies from even to somewhat lumpy, and projecting fiber 

 ends occasionally show. The pores may be described in terms of the surface 

 net. Of this, the gross fibers are 40 ll to 100 \x in diameter. They outline 

 meshes which are often nearly square and which are about 200 \x to 400 ll in 

 diameter. Within them, outlining what may be regarded as the proper pores, 

 are the smaller fibers which vary from only 5 ll to as much as 20 ll in diameter. 

 These outline meshes, which are from 70 ll to 100 ll, rarely reach 180 ll in 

 diameter. The oscules are 3 to 10 mm in diameter, the larger size being quite 

 uncommon. They are often only 1 to 2 cm apart. In the specimen from 

 Iwayama Bay, Koror, they had a tendency to be organized in rows. 



The ectosome is the special dermal skeleton described above, and the 

 endosome is a more simple fibro-reticulation with (as usual in this genus) a 

 minimum of protoplasmic or soft parts. 



The skeleton consists of fibers of rather typical spongin ; these are cored 

 with a few oxeas. These megascleres are usually 4 ll by 124 ll to 6 \x by 136 ll 

 in dimensions ; but, in Specimen No. M. 438, they were a little smaller, only 

 2 ll by 93 p. to 2.5 ll by 110 ll-. 



Ridley, 1884, page 183, described a sponge as Cladochalina diffusa from 

 the Indian Ocean; Burton, 1934, page 541, properly transferred this to the 

 genus Callyspongia, and extended its range throughout the East Indian re- 

 gion ; de Laubenfels, 1950, page 12, records it from the Hawaiian Islands; 

 and the present record would seem to indicate that it is spread extensively 

 throughout the western Pacific as well. 



Callyspongia psammophera, new 



Text Figure No. 52 



This species is here represented by the following : 

 U.S.N.M. No. 22831, My No. M. 107, here designated as type, collected 

 June 20, 1949, by diver at Ailing-lap-lap Atoll in the channel beside 



