26o 
b- second brachial not appreciably longer than the first 
c' proximal portion of the arms broad, very rugged, and with the articular 
tubercles very strongly developed (H a w a i i a n 1 s 1 a n d s) 7'it!:^osiis 
c- proximal portion of the arms only very slightly enlarged, smooth, 
without any trace of articular tubercles (Meangis Islands and 
Mol uccas) nai-esi 
I. Thaumatocriims tiaresi (P. H. Carpenter). 
P. H. Carpenter, Proc. Roy. Soc, vol. 28, p. 385 {Promachocrinus naresi). 
"Challenger" Reports. The Comatulae, p. 352, pi. 69, figs. 8 — \o {Projnachocrinus naresi). 
Stat. 122. i°58'.5N., i25°o'.5 E. Sangi Islands, northeast of Celebes. 1264 — 1165 Metres. 
I mutilated Ex. 
The centrodorsal is very low hemispherical with a strongly flattened dorsal pole, and 
measures 6 mm. in diameter. It bears XXXV cirrus sockets in three closely crowded alternating rows. 
The ten radials are in mutual apposition all around the calyx, being 
only slightly separated at the distal angles; they are short, projecting beyond 
the centrodorsal for a distance equal to from one third to one half the length 
of the first brachial. 
Dorsal "view of the '^\\& first brachials are approximately oblong, averaging twice as broad 
central portion of a ^g loiig ; the secoud brachials are similar, of about the same size or 
specimen of Tliauma- 
locrinus naresi from slightly shorter. 
Stat. .22. About natural ^j^^ ^^^^^^ ^^^^^^ ^j^^ ^j^^^j ^. ^^ ^j^^ x2.^\?\s to the distal edge of the 
size. (Courtesy of the '^ ° 
U.S. National Museum), fourth brachial (the first syzygy) measure 6 mm. 
Thatwiatocriniis dorea/is, which I recently combined with 77/. itarcsi as a s\-nonym, 
is in reality a perfectly good species. It is readily distinguished from the allied species by the 
small size of the first and the large size of the second brachials, the latter being nearly or 
quite twice as large as the former. In Tk. naresi the first three brachials are all of about the 
same size. 77/. borealis is largfer and more ruggfed and robust than 77/. naresi. 
Pentametrocrinus A. H. Clark. 
Key to the Species of the Genus Pentametrocrinus. 
a' A pinnule on the second brachial; cirri greatly elongated, straight for most 
of the length, gently recurved at the tip, tapering to a point, composed of 
18 — 22 segments; all the cirrus segments (except the basal) greatly elongated; 
terminal claw minute, conical (Bay ofBengal to the East Indies, the 
P h i 1 i p pi n e I si a nds a n d so u t h e r n J apa n) z'arians 
a" The first pinnule on the fourth brachial 
b^ cirri greatly elongated, straight for most of the length, gently recurved at 
the tip, tapering to a point, composed of 25 — 30 segments; all the cirrus 
