THE SPONGES OF THE WEST-CENTRAL PACIFIC 235 



Tethya. Their dimensions are 11 /* by 500 /x to 17 fi by 1250 p. The micro- 

 scleres include the usual dermal spherasters, in this case about 55 p in 

 diameter, and also include small asters scattered through the flesh. These latter 

 are eutylasters about 6 /a to 10 jx in diameter; some have only four or five rays, 

 more have eight or ten rays. In addition, there are abundantly present oxy- 

 spherasters, about 25 /* in total diameter, of which it is true that one or more 

 of the rays of each spicule have a dichotomous branching a short distance 

 from the end. 



This species was described as Tethya actinia by de Laubenfels, 1950, 

 page 116, from Bermuda, and is sharply characterized by the dichotomous 

 branching to the ends of the rays of the intermediate sized asters. Brondsted, 

 1934, page 5, described it as occurring in the East Indies, but he erroneously 

 identified his specimens as being T. diploderma. The species is probably 

 circumequatorial. 



GENUS LIPASTROTETHYA, new 



This genus is here established in the family Tethyidae, to have as type 

 the following new species, Lipastrotethya ana. It is characterized by being 

 exceedingly like Tethya in general appearance, fleshy structure, and mega- 

 scleres, but differs sharply by complete lack of the characteristic microscleres. 



The generic name selected is derived first from a Greek prefix meaning 

 "without," and second with reference to the word "aster," and third to the 

 genus Tethya. That is to say, this is Tethya without asters. 



Lipastrotethya ana, new 



Text Figure No. 162 



This species is here represented by the following: 



U.S.N.M. No. 23094, My No. M. 476, here designated as type, collected 

 August 17, 1949, by diver in the northeast corner of the lagoon in the 

 lee of Givry Islet at Kuop Atoll. The depth was 2 meters, and the sub- 

 strate was dead coral. 



U.S.N.M. No. 23096, My No. M. 478, collected at the same time in the same 

 general vicinity. 



Text Figure No. 162. Spicules of Lipastrotethya ana, X 182. A: Strongyle. B: Fila- 

 mentous spicule, which may be a juvenile strongyle. 



