THE SPONGES OF THE WEST-CENTRAL PACIFIC 



165 



Text Figure No. 107. Spicules (styles) of Ulosa spongia, X 782. 



The exterior color in life was yellow, but the interior was pale and dull. 

 The consistency was very spongy. 



The surface, as noted above, is very uneven and rough. The pores and 

 oscules were impossible to discriminate from the cracks and rugosities in the 

 surface. 



The ectosome is quite definite, but only 10 fx thick. It is a dermis very 

 full of spicules in confusion. The endosome was remarkably like that of the 

 genus Spongia, with a fibro-reticulation. 



The skeleton consists primarily of fibers of spongin, but these fibers are 

 packed with spicules, the diameter of the whole being about 50 p.. The 

 spicules consist of smooth styles, about 5 /x by 500 jx in dimensions. Quite 

 a number are smaller, about 2 p. by 165 jx ; this may possibly constitute a sec- 

 ond category, but the opinion here is expressed that the smaller ones are 

 merely immature forms of the other spicules. 



The type of Ulosa is a sponge first described as Spongia angulosa by 

 Lamarck, 1814, page 376, from the Australian region. Its spicules are very 

 much smaller than those of the present species. The same is true of that 

 Ulosa which was first described as Strongylacidon intermedia by Burton, 

 1934, page 550, from the same region. The next species which was referred 

 to Ulosa is that first described as Stylotella topsenti by Arnesen, 1920, page 

 18, from the region of western Africa. Its spicules are half as long, but 

 four times as thick as those of Ulosa spongia. This species was incorrectly 

 referred to Hymeniacidon by de Laubenfels, 1936, page 137, but correctly 

 referred to Ulosa by the same author in the same reference on page 126. 



The species name refers to the resemblance of the fibers to those of 

 Spongia. 



GENUS STYLOTRICHOPHORA Dendy 

 Stylotrichophora rubra Dendy 



Text Figure No. 108 



This species is here represented by the following: 

 U.S.N.M. No. 22845, My No. M. 136, collected July 5, 1949, by diver at 

 Ebon Atoll from the Pearl Pool which is in the western portion of the 



