THE SPONGES OF THE WEST-CENTRAL PACIFIC 119 



nated by typical acanthostyles, but in very small numbers so that they may be 

 easily overlooked. These are about 3 fi by 90 /a in dimensions in the speci- 

 mens of antrodes from the Marshall Islands but are somewhat larger, about 

 6 (i by 120 [i, in the specimens from further west such as Ponape, the Palaus, 

 and Guam. Spicules of this type seem to be entirely and completely lacking 

 from the abnormal specimen, No. M. 444. It may belong in Milene. 



An item in the literature which most nearly resembles antrodes, at least 

 superficially, is a photograph by Lendenfeld, 1888, "Sponges of the Aus- 

 tralian Museum," plate xi. This is now classified as Fasciospongia turgida 

 and presumably has no proper spicules. Its cavernous nature well may be 

 due to macerated condition. 



The species name is derived from the Greek word meaning "cavernous." 



GENUS MYRMEKIODERMA Ehlers 

 Myrmekioderma tylota, new 



Text Figure No. 74 



This species is here represented by the following : 



U.S.N.M. No. 23059, My No. M. 439, here designated as type, collected 

 August 3, 1949, by diver in southwest Ponape (Kiti) near Toletik Isle 

 from a reef in the lagoon near shore, where this species was abundant. 

 The depth was 4 meters, and the substrate was dead coral. 



U.S.N.M. No. 23041, My No. M. 420, collected August 1, 1949, by diver 

 from east Ponape (Matalanim) from a reef near an entrance to the 

 lagoon. The depth was 5 meters, and the substrate was dead coral. 



U.S.N.M. No. 22887, My No. M. 187, collected August 3, 1949, by diver 

 from southwest Ponape (Kiti) near Toletik Isle from a reef in the 

 lagoon near shore. The depth was 4 meters, and the substrate was dead 

 coral. 



This species is incrusting when young but soon becomes rounded masses, 

 sometimes nearly hemispherical. These masses range from 2 to 4 cm in 

 vertical dimensions and from 6 to 8 cm to 10 by 10 cm in horizontal di- 

 mensions. 



The color in life was predominantly ochre yellow; it was, sometimes, 

 but not always, duller in the interior. The exterior was regularly covered 

 with considerable quantities of debris — diatoms and bits of sand — so that it 

 appeared dark drab, with the exception of the pore cracks, to be mentioned 

 below, which showed yellow through the detritus. The consistency was soft, 

 very much like that of cheese. 



The surface is covered throughout with wide, low protrusions, rounded 

 in outline, or polygonal because of crowding. Their diameter is about 7 to 

 10 mm, and they rise about 1 mm. On the other hand, this structure could 

 be described as a fairly level surface cut up by pore grooves 1 mm deep and 



