SIDONOPS BICOLOR. 227 



Sidonops reticulata (Bow-grb^nk). 



Lendenfeld, Tierrcich, 1903, 19, p. 102. 



Geoilia reliculata Bowerbank, Proc. Zool. soc. London, 1874, p. 300, plate 46, figs. 14-20. Sollas, Rept. 

 voy. "Challenger," 1888, 25, p. 253. 



Massive. Dry: white. 



Atnphioxes: 1.75 mm. by 19 /i. Orthoplagiotriaenes: rhabdome 2 mm. 

 by 31.2 //; clades 237.5 /t long; cladome 450 /z broad. Protriaenes: (mesopro- 

 triaenes ?): clades 250 fi long; cladome 120 fi broad and 206 n high. Ana- 

 triaenes: clades 144 /i long; cladome 150 /z broad and 125 /thigh. 



Oxyasters: no centrum; total diameter 25.4 /<. Small strongylasters: 

 total diameter 8.5 fi. Sterrasters: spherical, small. 



? Eastern Pacific. Mexico. 



Sidonops bicolor Lendenfeld. 

 Ante, p. 46. 



Irregularly tuberous, elongated or flattened. In spirit: whitish to reddish 

 or purple-brown, some parts of the surface usually much darker than othei-s. 



Stout amphioxes: rather blunt; 2.3-5.6 mm. by 36-105 fi. Stout styles: 

 rare, not in all specimens; 4 mm. by 100-200 /z. Slender amphioxes: 3.5-9 mm. 

 by 15-40 /t. Plagiotriaenes: rhabdome usually 2.1-4 mm. by 82-110 /.i at the 

 cladome, and 3-10 // more a little below, at the thickest point; sometimes re- 

 duced in length, cylindrical and rounded; clades, concave to the rhabdome, 

 nearly straight, or concave to the rhabdome proximally and convex to it distally, 

 blunt, 280-700 /< long; clade-angles 103-122°. 



Large choanosomal oxyasters: from one to twelve, most frequently from 

 seven to nine, distally spined rays, 1-2.8 /z thick; centrum 2.8-6 /«, whole aster 

 19-34 /(, in diameter. Oxysphaerasteis: from twelve to twenty-five distally 

 spined rays, 0.7-2.5 /j. thick; centrum 4-10 /«, whole aster 10-23 /«, in diameter. 

 Strongylosphaer asters: usually from nine to thirt}', very rarely only one, distally 

 spined rays, 0.7-3.5 n thick; centrum 4-12 ji, whole a.ster 9-21 /.«, in diameter. 

 Sterrasters: 130-170 by 100-133 by 77-97 //. 



Northeastern Pacific. West coast of North America; from 33° 18' N. to 

 Monterey Bay. "Albatross" Stations 2958, 2981, 3168, 4420, 4531, 4551. 



