THE SPONGES OF THE WEST-CENTRAL PACIFIC 99 



B 



— r 



Text Figure No. 60. Spicules of Pellina eusiphonia. A: Oxea of commonplace shape, 

 X 182. B: Two ends of a partially strongylote spicule, X 781; the central portion is 



not shown. 



The ectosome is a tangental reticulation of isodictyal nature. The endo- 

 some is little more than a minute layer of flagellate chambers but does contain 

 some additional isodictyal reticulation and some spicules in confusion. 



The skeleton consists entirely of oxeas, which sometimes have a slightly 

 strongylote or rounded termination at both ends. Most of them are about 

 10 /x by 370 fx, but a few are as small as only 2 /x by 110 [x. 



Ridley, 1884, page 414, described Pellina eusiphonia from the East 

 Indian region. It may be that there are some specific differences between 

 it and this specimen from Ebon, but Ridley's description does not make such 

 clear. Therefore, the identification is here made with eusiphonia. 



Pellina pinella, new 



Text Figure No. 61 



This species is here represented by the following : 

 U.S.N.M. No. 22853, My No. M. 147, here designated as type, collected July 

 5, 1949, by diver in a miniature lagoon at Ebon Atoll near the south 

 corner of the lagoon. The depth was 2 meters, and the substrate was 

 dead coral. 



This species consists of hollow erect cylinders with walls only about 

 50 ix thick. The diameter of the tubes is about 3 mm, and the vertical measure- 

 ment at least 11 mm. 



The color in life was white, and the consistency was fragile. 



The surface is comparatively level, although the meshes of the skeleton 



cause it to appear micropunctiform. The pores are about 70 \x in diameter 



and 140 [x apart, center to center. The oscule is represented only by the 



distal termination of the tube. 



Text Figure No. 61. One of 



the spicules (oxea) of 



Pellina pinella, X 781. 



