102 THE SPONGES OF THE WEST-CENTRAL PACIFIC 



The surface is smooth, with abundant small but very contractile pores. 

 The oscules are represented by the hollow terminations of the ascending 

 processes and are, therefore, some 6 mm in diameter and about 2 or 3 cm 

 apart. 



The ectosome consists of a tangental isodictyal reticulation, and the endo- 

 some is also permeated by an isodictyal reticulation. 



The skeleton consists of oxeas, often about 12.5 /x by 250 /x, but occa- 

 sionally as small as 5 jx by 225 /x in dimensions. The latter are probably 

 juvenile. 



Lamarck, 1814, page 375, described Spongia carbonaria, stating that it 

 was from the West Indian region, but his specimens conform very closely 

 to the present ones from the Palaus. De Laubenfels, 1936, page 68, trans- 

 ferred carbonaria to Pellina, and recorded it from the West Indian region, 

 but although it was from the supposed type locality, discovered the spicules 

 to be much smaller than those recorded by Lamarck, and found them to be 

 often strongylote rather than typical oxeas. If Lamarck made a mistake in 

 the locality from which the specimens came, as is quite possible, one would 

 conclude that these from the Palaus represent typical carbonaria, and those 

 from the West Indies deserve a new specific name. In this case the species 

 would not be world wide. If Lamarck is correct in his statement as to local- 

 ity, then this may be regarded as a circumequatorial species. 



Pellina pulvilla (Thiele) de Laubenfels 



Text Figure No. 64 



This species is here represented by the following : 

 U.S.N.M. No. 23145, My No. M. 529, collected September 20, 1949, by diver 

 on the northwest shore of Guam in Dungas Bay near Agana. The depth 

 was 1 meter, and the substrate was dead coral. 



The shape is ramose, the branches being tubes about 7 mm in diameter 

 with walls 1 mm thick. A vertical dimension of at least 5 cm is reached. 

 It is noteworthy that many of these processes anastomose ; this is not common 

 within the genus Pellina. 



The ectosome color in life was nearly black, but the endosome was quite 

 pale. The consistency was very soft. 



The surface is even but conspicuously provided with pores, about 100 /x 

 by 130 /x in dimensions and about 700 /x apart, center to center. The oscules 

 range from 2 to 5 mm in diameter and are located at the ends of the 

 processes. 



The ectosome is not detachable but is a tangental reticulation of spicules. 

 The fact that it does not easily come loose makes it seem a little dubious that 

 this is a Pellina. The endosome is quite noteworthy because the flagellate 



