THE SPONGES OF THE WEST-CENTRAL PACIFIC 91 



apart. In many regions the so-called conules are so broad at the base that 

 the term undulating is more applicable than conulose. The pores are about 

 0.3 mm in diameter, and there is one for about each square mm. The oscules 

 are 4 to 7 mm in diameter and are about 3 to 6 cm apart. Each immediately 

 branches into several large canals, which are conspicuous. 



The ectosome is an obvious tangental spicular reticulation, reminiscent 

 of the dermal skeleton of Callyspongia but less well provided with secondary 

 spongin fibers. 



The ectosome is little more than a continuation of the endosome, but in 

 it a conspicuous fibro-reticulation shows, the fibers being simply those of the 

 whole sponge. It is noteworthy that in between these are meshes reminiscent 

 of those which characterize the genus Callyspongia. The endosome is fibro- 

 reticulate. 



The skeleton consists of fibers which are rather crowded with spicules 

 but do definitely contain spongin. These vary from about 40 li to 140 ll 

 in diameter, and they outline meshes which are often triangular but some- 

 times polygonal. As noted above, these may be walled in with a sieve- 

 like pattern that is more or less isodictyal. The megascleres are oxeas, some- 

 what hastate, 6 ll by 140 /x in dimensions. The microscleres are sigmas, 

 16 ll in chord length. 



This species bears considerable resemblance to the genotype of Gelliodes, 

 which was originally described as Axos fibulata by Carter, 1881, page 383, 

 and transferred into this genus by Ridley, 1884, page 426. Fibulata is an 

 Australian species. The color in life is not known, and the spicules are 

 about twice as long as those of callista. Its pores and oscules are not de- 

 scribed by Carter. Were more data about it to become known, more re- 

 semblance between it and callista might be revealed, but on the other hand 

 more differences might appear instead. 



The new species name is derived from the Greek word meaning "beau- 

 tiful." 



GENUS IOTROCHOTA Ridley 

 Iotrochota pella, new 



Text Figure No. 55 



This species is here represented by the following : 



U.S.N.M. No. 22958, My No. M. 332, here designated as type, collected 

 June 28, 1949, by diver at Majuro Atoll in the east end of the lagoon, 

 near Rita (or Jarej) Islet. The depth was 4 meters, and the substrate 

 was dead coral. 



U.S.N.M. No. 22967, My No. M. 341, collected July 2, 1949, by diver at 

 Majuro Atoll near the south side of the lagoon near Rairok Islet. The 

 depth was 2 meters, and the substrate was dead coral. 



