250 



GEODIA MEDIA. 



rounded, fully developed ones conical, pointed, convex to rhabdome throughout 

 their length, 90-260 [i long, over 200 ju only in monaenes; clade-angles 113-147°. 



Oxyasters: from six to fifteen smooth, conical rays; total diameter 17-32 /i. 

 Oxysphaerasters: from five to thirty and more conical rays, 1.4-4 fi thick, rays 

 usually smooth, rarely with one or two stout spines; centrum 4-12 pi, whole aster 

 16-31 a, in diameter. Sterrasters: 55-62 (Lendenfeld, 1888, 67 fi) by 50-59 by 

 45-54 ft. 



Southwestern Pacific. East coast of Australia ; Broughton Island. 



Geodia media Bowerbank. 



Proc. Zool. soc. London, 1873, p. 13, plate 2, figs. 24-29. Lendenfeld, Ante, p. 191. 

 Sunops (?) media Sollas, Rept. voy. "Challenger" 1888, 25, p. 26G. 

 Sidonops media Lendenfeld, Tierreich, 1903, 19, p. 103. 



The following description is also based on an examination of part of the 

 type specimen in the British Museum. 



Massive, irregular, with depressions, in which are conspicuous sieve-covered 

 canal-entrances; more rarely digitate. In spirit and dry: light brown or buff 

 yellow. 



Large aniphioxes: slender and stout; 1-1.7 mm. by 23-51 /x. Large styles: 

 not numerous; 0.9-1.3 mm. by 30-50 /x(not mentioned by Sollas, 1888). Large 

 irregular rhahds: angularly bent or with one or more branch-rays, often numer- 

 ous; dimensions as in the regular amphioxes and styles (not mentioned by 

 Bowerbank, 1873, or Sollas, 1888). Minute dermal styles: attenuated towards 

 the rounded end; 140-265 b}^ 2-6 /i (not mentioned by Bowerbank, 1873-, or 

 Sollas, 1888). Slender plagiotriaenes: rhabdome 1-1.6 mm. by 17-30 /j.; clades 

 strongly concave to rhabdome throughout their whole length, 160-260 pt long; 

 clade-angles 107-114°. Stout plagiotriaenes: rhabdome 0.8-1.7 mm. by 30-80 /i 

 (Sollas, 1888, 45 (error 450) fi); clades slightly concave to rhabdome or nearly 

 straight, 110-310 /jl long; clade-angles 105-120°. Mesomonaenes: orthoplagio- 

 or proclade; rather scarce; rhabdome 1.7-2.5 mm. by 4-10 ;t; clade 17-50 p 

 long; clade-angle 32-89°; epirhabd 40-75 p. long (not mentioned by Bower- 

 bank, 1873, or Sollas, 1888). Amphiox-like derivates of the mesoclades: of similar 

 dimensions; with the clade more or less completely suppressed (not mentioned 

 by Bowerbank, 1873, or Sollas, 1888). Anatriaenes: scarce; rhabdome 10-15 p. 

 thick; clades 23-35 /xlong; clade-angles 44-52° (not mentioned by Sollas, 1888). 

 Mesanatriaenes: very rare, not always present; rhabdome 0.8 mm. long, termi- 

 nally thickened and rounded; clades similar to those of the anatriaenes; epi- 

 rhabd 165 p long. 



