210 PROCEEDINGS OF THE NATIONAL MUSEUM. WO, 2OOGH%, 
KEY TO THE FAMILIES OF COMATULIDA HAVING RECENT REPRESENTATIVES. 
Ge, IWATESS CRAIG jORESANE es _THAUMATOCRINIDAS. 
a’. No orals 
b. Basals present; cirrus sockets bordered anteriorly and laterally by an ele- 
Varted) id Serica Se ee ie a eee a eee ATELECRINID AS. 
b’. Basals metamorphosed into a rosette; cirrus sockets with no antero-lat- 
eral ridge. ; 
Co ATMS< Undivided. = See eS ke 5 ie ees nape een HUDIOCRINID A. 
ce’. Arms divide at least once. 
d. Mouth central, anus lateral; oral pinnules with the tips not furnished 
with a comb. 5 
e. Costals articulated. 
f. Middle and distal pinnules sharply triangular and styliform; cen- 
tral cavity of centro-dorsal very small. 
g. Muscular fossee on distal face of radials very high, much longer 
than broad; terminal pinnules very short, not extending be- 
VON ti Pv. O Lait nes eee eee eee eee eee THALASSOMETRIDA. 
g’. Muscular fossee harrow and transversely linear; terminal pin- 
nules extending far beyond tip of arm______— TROPIOMETRID 2. 
f’. Middle and distal pinuules round, the articulations swollen; cen- 
tral cavity of centro-dorsal very large. 
g. Lower pinnules slender, like the following; opposing spine when 
present terminally situated; some or all of the cirrus joints 
‘* dice-box shaped;” muscular fossz on faces of radials meet- 
ing in the median line, and separated from the ligament fossz 
by a strong diagonal ridge_________ ANTEDONID (restricted). 
g’. One or more of the lower pinnules enlarged, and much stouter 
than the succeeding; opposing spine, when present, centrally 
Situated; cirrus joints with more or less convex borders; 
muscular fosse entirely and widely separated from each 
other, but not separated by a diagonal ridge from the liga- 
THETA O SS sees ace Fe ss eee ee eee ee HIMEROMETRID 2. 
Ci BOOStALS MUIINCE CL LON aa SIV ZY ey cg Te ZY GOMETRIDZ. 
d’. Mouth marginal, anus central; oral pinnules furnished with a ter- 
nome! Cowal) = * a eae See ee COM ANGI RION AD, 
This key is, so far as possible, based upon obvious external char- 
acters which can be appreciated at a glance; a detailed discussion of 
the families and their fundamental characters is reserved for a future 
paper. | | 
The geographical and bathymetrical range of the families is as 
follows: 
THAUMATOCRINID® (based upon a genus and species founded upon 
a single small, probably immature, individual) ; southwest of Mel- 
bourne, Australia; 1,800 fathoms. | 
ArELEcRINIDE (Atelecrinus) ; West Indies; coast of Brazil; Fiji; 
Hawaiian Islands; 291 to 610 (?809) fathoms. 
Evupiocrinipm (Ludiocrinus; Decametrocrinus); West Indies; 
coasts of southern Europe; coasts of Somaliland, and the Crozet Is- 
lands, eastward to the Meangis and Hawaiian Islands, northward to 
Japan; 103 to 1,800 fathoms. 
