248 



GEODIA ACANTHTYLASTRA. 



Geodia lophotriaena Lendenfeld. 

 Ante, p. 181. 



Cushion shaped. Inspirit: brownish. 



Large choanosomal amphioxes: 1.2-1.8 mm. by 25-42 /jt. Minute dermal 

 rhahds: mostly blunt amphioxes, rarely styles; 110-200 by 3-6 /i. Plagio- 

 triaenes: rhabdome 0.6-1.2 mm. by 25-35 /i, sometimes reduced in length and 

 rounded terminally; clades concave to the rhabdome throughout, 140-195 fi 

 long; clade-angles 102-114°. Dichotriaejies and other lophotriaenes: the former 

 more frequent than the latter; rhabdome 0.8-1.2 mm. by 35-59 fi; main clades 

 70 140 /«, end clades, of which there are in the lophotriaenes from three to five, 

 70-80 /t long; main clade-angles 105 130°; breadth of cladome 300-500 ft. 

 Mesoprotriaenes: rhabdome about 1.3 mm. by 4-9 n at the cladome, and 7-11 /x 

 at the thickest point near the middle; clades 44 80 jn long; clade-angles 32-41°; 

 epirhabd 38-60 long. Large anatriaenes: rhabdome 8-13 /x thick; clades 60- 

 85 ^( long; clade-angles 41-50°. Minute dermal anatriaenes: rhabdome 170- 

 210 by 1-3 n at the cladome, and 2-4 /( at the thickest point near the middle; 

 clades 4-9 pt long ; clade-angles 49-67°. 



Large oxyasters: from four to eleven smooth, conical rays, 1-2.2 fi thick; 

 centrum small; total diameter 15-41 /x. Sphaerasters: from seven to twenty- 

 two or more, usually cylindroconical, truncate, rarely conical and pointed, usually 

 spined rays, 0.8-2.4 /( thick; centrum 2-8 /t, whole aster 7-22 /«, in diameter. 

 Sterrasters: mostly 30-45 by 33-44 by 27-35 /<; a few larger ones, up to 58 fi 

 long, also observed, these perhaps foreign. 



? Southwestern Pacific. Probably New Zealand. 



Geodia acanthtylastra Lendenfeld. 

 Ante, p. 188. 



Irregularly spherical, oval or tuberous. In spirit: brownish white. 



Large amphioxes: 0.7-2.2 mm. by 14-40 Minute dermal rhahds: for the 

 most part amphioxes, styles also present, but rare; 150-300 by 3-15 jx. Minute 

 amphioxes: 41-53 by 1-1.2 p.; perhaps foreign. Plagiotriaenes: rhabdome 

 1.2 2.5 mm. by 40-77 /n; clades concave to the rhabdome throughout, or only 

 basally and distally straight, 160-260 /£ long; clade-angles 100-116°. Irregular 

 plagiotriaene-derivates: of similar dimensions; either with another clade besides 

 the three ordinary, or with bifurcate clades (some regular dichotriaenes were 

 observed, but these may be foreign). Mesoprotriaenes: rhabdome 2.3-3.3 mm. 



