326 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Actinometra strata VON GRAFF, Challenger Reports, Zoology, vol. 10, pt. 27, 1884, p. 20 (myzostomes) , 

 p. 29 (stations 186, 187; myzostomes). P. H. CARPENTER, Challenger Reports, Zoology, 

 vol. 26, pt. 60, 1888, p. 93. WHEELER, Mittheil. aus d. Stat. Neapel, vol. 12, 1896, p. 244 

 (myzostomes) . 



Actynometra strata FILHOL, La vie au fond des mers, 1885, p. 214 (Anilocra parasite; from Car- 

 penter) . 



Actinometra striata PERRIER, Memoire sur 1'organisation et le deVeloppement de la Comatule de la 

 Mediterranee, 1886, p. 107 (coloring matter; from Moseley, through Carpenter). BRATJN, 

 Centralbl. f. Bakteriol. u. Parasitcnkunde, vol. 3, 1888, p. 185 (myzostomes). 



Antedon (Actinometra) robustum (Liltken, MS.) A. H. CLARK, Vidensk. Medd. fra den naturhist. 

 Foreniug i K0benhavn, 1909, p. 146. 



Actinometra echinoptera var. meridionalis HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 

 1912, p. 417 (Hong Kong). 



Comatula (Comatula) Solaris A. H. CLARK, Unstalked Crinoids of the Siboga Exped., 1918, p. 26 

 (in key; range); p. 27 (same). 



Comatula (Comatula) Solaris var. hamata A. H. CLARK, Unstalked Crinoids of the Siboga Exped., 

 1918, pp. 26, 27 (in key; range). 



Comatula (Comatula) Solaris var. Solaris A. H. CLARK, Unstalked Crinoids of the Siboga Exped., 

 1918, pp. 26, 27 (in key; range). 



Diagnostic features . The large size and the occurrence of cirri which are com- 

 posed of 16-25 (usually about 20) segments separate this species from all the others 

 in the subgenus. The arms seem to be invariably 10 in number. 



Description. The centrodorsal is a small thin disk bearing marginal cirri in a 

 single more or less irregular row. 



The cirri are X-XXV (usually XV-XX), 17-24 (usually about 20). The first 

 segment is very short, the second is more than twice as broad as long, and those fol- 

 lowing slowly increase in length to the sixth-eighth, which are from half again as broad 

 as long to nearly as long as broad, then slowly decrease so that the outer are twice 

 as broad as long, the few terminal lengthening again so that the penultimate, which is 

 smaller than those preceding, is about as long as broad. The opposing spine is conical, 

 very small, and median to subterminal in position. The terminal claw is markedly 

 longer than the penultimate segment, slender in the distal two-thirds, and more 

 strongly curved proximally than distally. 



The row of cirri on the centrodorsal may be more less deficient, half of the cir- 

 cumference being sometimes without cirri. 



The radials are usually entirely concealed, but a small portion of their distal 

 lateral angles may be visible interradially. The IBr! are exceedingly short, from 

 six to eight or more times as broad as long, and are in close contact laterally. They 

 are united to the IBr 2 (axillaries) by syzygy, the line of union being perfectly straight. 

 The IBr 2 are nearly or quite four times as broad as long, broadly triangular, with the 

 lateral angles more or less sharp or slightly truncated and forming short sides which 

 are usually separated by a narrow V-shaped slit. 



The 10 arms are usually about 150 mm. long and are more or less flattened dor- 

 sally. They are narrow at the base and increase rather rapidly in width to the tenth 

 or twelfth brachial, from which point they very slowly taper distally. A low, narrow, 

 rounded keel, becoming conspicuous on the eighth brachial, often runs the entire 

 length of the arms, though it is as often absent. The first brachial is very short and 

 bandlike, from six to eight or more times as broad as long, with the proximal and 



