224 SIDONOPS ALBA. 



Sidonops califomica Lendenfeld. 

 Aiitp, p. IS. 



Elongate, tuberous. In spirit: yellowish white. 



Large choanosomal amphioxes: 1.2-2 mm. by 30-48 /«. Large styles: rare; 

 55 /t thick. Minute dermal styles: 175-290 by 3-7 //. Very minute amphioxes: 

 50 by 1 n, possibly foreign. Orthoplagiotriaenes: rhabdome 0.9-1.45 mm. by 

 20-78 ji: clades concave to the rhabdome, 160-400 /« long; clade-angles 104- 

 120°. Mesoplagioclades: rhabdome 6-15 /i thick; from one to three clades, 

 20-42 f.1 long; clade-angles 102-118°. Anatriaenes: rhabdome 10-17 /i tliick; 

 clades stout, 22-45 fi long, clade-angles 45-66°. Anadiaenes and anamonaenes: 

 of similar dimensions; rare. 



Large choanosomal oxyasters: six to fourteen rays, 1.7-3 p. thick, covered 

 cver)"vvhere, except at the base with spines; total diameter 22-48 p; size in 

 invei-se proportion to raj'-number. Small oxysphaerasters: 7-9 p in diameter. 

 Small strongylosphaerasters: from six to seventeen spined rays, rounded termi- 

 nally and 0.8-1.5 ii thick; centrum 2-3.5 /i, whole aster 4.5-9 /<, in diameter. 

 Starasters: 116-130 by 97-105 by 70-90 u. 



Eastern Pacific. West coast of North America; 22° 52' N. "Albatross" 

 Station 2829. 



Sidonops alba (Kieschnick). 



Lendenfeld, Ticrrcich, 19()o, 19, p. 100. 



Synops alba Kieschnick, Zool. anz., 1896, 19, p. 529. 



Syilonops alba (Kioschnick) Thiele, Abhandl. Senckenb. gesellsch., 1900, 25, j). 46, plate 2, fig. 16a-h. 



Irregular, depressed, with attached foreign bodies. Dirty brownish white. 



Large choanosomal amphioxes: 2.5 mm. by 30 /(. Large styles: rare, of 

 similar dimensions as the large amphioxes. ^[inute dernud styles: 250 by 

 5 /(. Plagiotriaenes: rhabdome 2 mm. long; clades 450 /« long. Mesoproclade- 

 derivates: monaene or diaene; clades reduced, short; total length of spicule 

 3 mm.; its thickness 14 ;<; epirhabd 80 /i long. Large anatriaenes: rhabdome 

 2.5 mm. by 14 /<; clades, strongly recur\'ed, about 20 p long. Minute dermal 

 anaclades (Thiele, 1900, exotyles): triaene, or, more rarely, diaene or monaene; 

 rhabdome 170 ;« long and about as thick as the minute dermal styles. 



Oxyasters: a smaller kind with numerous rays, not quite up to 15 /( long; 

 and a larger kind with few, rough rays, up to 30 p long. Small strongylosphaer- 

 asters: rays short and stout; centrum large; total diameter about 8 p. Star- 

 asters: 110-90 p. 



Western Pacific. Ternate. 



