THE SPONGES OF THE WEST-CENTRAL PACIFIC 97 



single oscule which immediately branched into five or six divergent descend- 

 ing or ascending canals. In a dried specimen, the pores again are in evi- 

 dence ; they are 300 /a in diameter when affected by drying, and appear to be 

 as common as one p. per each square mm. 



As noted above, the ectosome contains considerable foreign material and 

 otherwise is extremely irregular. The endosome is a fibro-reticulation. The 

 skeleton consists of fibers about 120 p. in diameter, with a central third, 40 p. 

 in diameter, profusely cored with spicules. The meshes are rounded and 

 extremely irregular in size, some as small as 80 /x by 150 ju, and others as 

 much as 1 mm or more in diameter. The spicules are oxeas, 2.5 p in diam- 

 eter and about 87 p. to 95 p. long. The ends show some tendency to be 

 hastate. 



The species ada is unique within the small genus Protophlitaspongia for 

 its very small spicules and for the presence of sand in the dermal region. 



The species' name is selected for brevity, because the genus name is long. 

 It has no special translation or significance. 



Protophlitaspongia aga, new 



Text Figure No. 59 



This species is here represented by the following : 

 U.S.N.M. No. 23124, My No. M. 506, here designated as type, collected Sep- 

 tember 2, 1949, by diver near Ngarebagal Islet northwest of Koror in 

 the Palau Islands. The depth was 3 meters, and the substrate was dead 

 coral. 



The shape is ramose with projections. The branches are about 2 cm in 

 diameter, and the vertical measurement at least 21 cm. 



The ectosome and endosome color in life was blue, verging on lavender. 

 The consistency was sticky and slimy, very much like Protophlitaspongia ada. 



The surface is profusely covered with holes and projecting fibers. The 

 latter often protrude as much as 3 or 4 mm. The pores are of all sizes, 

 from some which are minute, even under the microscope, to others of 2 or 

 3 mm. The latter are probably oscules, but it is not possible to draw a sharp 

 line between inhalant and exhalant aperatures or even to be sure that all the 

 openings led to canals. 



Text Figure No. 59. Three of the spicules of Protophlitaspongia aga, X 781. 



