350 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The 2 specimens from Cooktown, Queensland, recorded by Hartlaub have a very 

 small centrodorsal. Their posterior arms are markedly shorter than the anterior 

 and are ungrooved. 



The specimen from Albany Passage in the Australian Museum is a fine example, 

 with the cirri XIX, 14-15, from 10 to 12 mm. in length. 



The specimen labeled Port Jackson has the cirri XVI, 11-13, 10 mm. long and the 

 arms 100 mm. long, somewhat swollen basally. 



In a specimen from Warrior Reef, as noted by Bell, the characteristic keel on 

 the lower pinnule segments is developed. The cirri do not seem to have been more 

 than XII, and the number of cirrus segments would appear to be less than 15. 



Regarding the specimens from Alert station 144, probably Thursday Island, 

 Bell noted that they were somewhat smaller than those described under the name 

 robusta by Carpenter, and that the lower brachials are not so distinctly knobbed, 

 while there is a very faint carination on the basal segments of P 2 . 



Professor Doderlein's specimens from Thursday Island have the cirri VI-IX, 

 12-14; a few of the segments are longer than broad. On one specimen with an arm 

 length of from 65 to 42 mm., Pj is about 14 mm. long. In another with the arms from 

 50 to 30 mm. long, PI is about 18 mm. long. The pinnules of the first 2 pairs are long 

 and slender, standing upright with the distal portion curled over. The comb is 

 restricted to the tip, and is sometimes prominent. The pinnules of the second pair 

 are shorter than those of the first pair. Both pinnules of the second pair bear on 

 the second segment, and sometimes also on the third and fourth, a high sharp keel 

 which is occasionally only feebly developed. The following pinnules extend hori- 

 zontally; they are remarkably broad and the tip is not incurved. The tip of the 

 pinnules of the third pair shows only a slight tendency to be incurved. These pin 

 nules have no terminal combs, and the proximal segments have no keels. P 3 and P 4 

 are of about equal size and are smaller than P 2 . The pinnules following become longer 

 again. In the outer half of the arms the pinnules again become slender. Two or 

 three of the shorter arms are ungrooved. The dorsal keel on the arms is slightly 

 developed. The disk is smooth. The color is red-brown. A young specimen with 

 the arms 10 mm. long has X cirri, of which the segments are considerably longer than 

 broad. All the pinnules are slender. 



In Comatula pectinata, specimens with more than 10 arms are always of the slen- 

 der-armed type, the stout-armed form never, so far as known, having more than 10 

 arms. 



The difference in length between the grooved anterior and the ungrooved pos- 

 terior arms reaches a maximum in this species (see vol. 1, pt. 1, figs. 45, a, b, p. 79; 

 vol. 1, pt. 2, fig. 163, p. 86), the posterior arms sometimes being scarcely one-third 

 the length of the anterior. 



The restriction of the ambulacral grooves is sometimes, as in the much smaller 

 C. micraster, carried to an extreme, only 4 of the arms being grooved, while 6 are 

 uugrooved. 



The articulation between the elements of the IBr series and that between the 

 first 2 brachials apparently always begin as a typical synarthry, later developing 

 along two different lines. In some cases the articulations simply become closer and 



