A MONOGRAPH OF THE EXISTING CRINOIDS 407 



P 8 and P 9 are 11 mm. long. All these pinnules have 14 or 15 segments. The pinnules 

 following increase hi length to about P, 7 , which is 16 mm. long with 22 segments which 

 at first are short and, slowly increasing in length, become about as long as broad on 

 the tenth and twice as long as broad terminally. There are about nineteen pairs of 

 these long pinnules, after which the pinnules decrease in length and very slightly in 

 stoutness. A distal pinnule (the twelfth from the arm tip) is 11 mm. long with 18 

 segments of which the first is more than twice as broad as long, the second is nearly 

 half again as broad as long, the third is slightly longer than broad, and those following 

 slowly increase in length becoming twice as long as broad distally, the terminal five 

 tapering abruptly so that the last is minute. 



A smaller and perhaps more typical specimen from Port Stephens (U. S. N. M., 

 35481) with 17 arms 50 mm. long and the cirri 30 mm. long differs in having the cirri 

 apparently irregularly arranged on the centrodorsal, although there are indications 

 of -20 columns ; in having the cirrus segments more uniform in size, none of them longer 

 than broad ; and in having the pinnule segments shorter. 



Notes. Speaking of the 147 specimens collected by the Endeavour (1) 11 miles 

 east-southeast of the Clarence River, (2) 8 miles east of Sandon Bluffs, (3) 6 miles 

 east of Cape Hawke, (4) between Port Stephens and Newcastle, (5) in Shoalhaven 

 Bight, and (6) on the southeast coast of Australia, Dr. H. L. Clark said that these 

 show no tendency to intergrade with P. macronema, fully justifying my separation 

 of the two forms. 



Six specimens from east-southeast of Clarence River that I examined at the Muse- 

 um of Comparative Zoology (No. 716) have 12, 13 (3), 15 and 20 arms; the three with 

 13 arms are small. Six specimens from between Port Stephens and Newcastle (No. 

 715) have 14, 16, 18, 19 (2), and 21 arms. 



The two specimens from Broughton Island are both small. 



Speaking of the 55 specimens from Thetis stations 10, 12, 28, and ? , Dr. H. L. 

 Clark said that the smallest has the 10 arms only 16 mm. long, but nevertheless shows 

 the adult specific characters fairly well; the centrodorsal is markedly conical, the X 

 cirri have each about 40 segments, and the pinnules are decidedly prismatic. In the 

 largest specimen there are 18 arms 60 mm. long, and the cirri have over 70 segments. 

 The color of all the specimens (in alcohol) is brown, but the shade varies considerably, 

 some individuals being decidedly purplish while others are yellowish, or more rarely 

 somewhat reddish. 



A specimen from Thetis station 10 in the Museum of Comparative Zoology (No. 

 374) has 14 arms; three from Thetis station 12 (No. 373) have 11 and 13 (2) arms. 



The specimen from off Port Halliday is small with 10 arms 20 mm. long and the 

 cirri about XV, 47-49, 17 mm. long. The smaller cirri are of an undeveloped type 

 but the longer have distally taken on the characters of those of the adult. The cirrus 

 sockets are arranged in two columns in each radial area with a more or less marked 

 miclradial space between them as in Pterometra and in many of the Thalassometridae. 



The four specimens from Cape Hawke are of medium size with 12, 14, 17 and 18 

 arms. The largest has the arms 50 mm. and the cirri 40 mm. long. 



The specimen from off Barranjoey is medium sized, stout, with 18 arms. 



The eight specimens from Port Stephens in the British Museum recorded by 

 Prof. F. Jeffrey Bell are fine typical examples of the species. 



