496 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



d'. First brachial never bearing a pinnnle. 



e\ Proximal pinnules more slender than the succeeding; terminal comb 

 short, with long curved teeth, appearing at intervals along the 

 distal pinnules (10) Comaster. 



e\ Proximal pinnules stouter than the succeeding; terminal comb long 

 with short rounded teeth, confined to the proximal pinnules. 



(11) COMANTHUS. 

 SUPPLEMENTARY KEY TO GENERA CONTAINING SPECIES WITH TEN ARMS ONLY. 



a\ Six pinnules following the first pair absent; large side plates developed 

 along the pinnule ambulacra ; opjiosing spine forked or branched. 



(1) COMATILIA. 



a". All pinnules present; no ambulacral plating; opposing spine single. 



b\ IBri and - and first two bi'achials united by syzygy (2) Comatula. 



b". IBi'i and 2 and first two brachials united by synarthry, 

 • c\ Cirri without dorsal spines or projections. 



(Z\ First two pinnules much stouter than the succeeding; cirri long, 



slender, and numerous (XL) (3) Cominia, 



(f. First two pinnules more slender than the succeeding; cirri short and 



stout, few in number (to XXVII) (4) Comactinia. 



c^ Cirri with dorsal spines or projections. 



d^. Distal cirrus joints (except the penultimate) considerably longer than 

 broad; synarthrial tubercles not developed; distal pinnules exceed- 

 ingly slender, with greatly elongated joints which have expanded 



articulations (5) Leptonemaster. 



(f. Distal cirrus joints considerably broader than long; synarthrial 

 tubercles prominent ; distal pinnules comparatively stout, the joints 

 rarely over twice as long as broad, the articulations not ex- 

 panded (6) Comissia. 



supplementary KE\' to GENERA CONTAINING MULTIBRACHIATE SPECIES. 



«'. IBri and 2 and first two joints beyond each axillary united by syzygy. 



(2) Comatula. 



fl^ IBi'i and 2 and first two joints beyond the first axillary united by synarthry. 



&\ First brachial bearing a pinnule; first brachial syzygy between the second 



and third brachials. 



c\ Brachials in distal half of arm exceedingly short, almost discoidal ; 



ambulacra naked ( 7 ) Capillasteb. 



(f. Brachials in distal half of arm triangular or very obli(iuely wedge- 

 shaped, nearly or quite as long as broad; pinnule ambulacra with 



large side plates (8) Nemaster. 



b°. First brachial never bearing a pinnule. 

 e\ Division series all 2; first brachial syzygy between the first two brachials 



on all but the outermost arms (9) Comatella. 



cl Several or all of the division series 4 (3-f4). 



d^. Proximal pinnules more slender than the succeeding; combs occur at 



intervals along the distal pinnules (10) Comaster. 



(Z^. Proximal pinnules stouter than the succeeding; no combs on the 

 distal pinnules „_ (11) Cjqman'EHUS. 



