300 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The terminal comb on the proximal pinnules is composed of 15 teeth which are 

 long and slender, shaped like an arrowhead with the point blunted. 



All of the arms bear ungrooved pinnules in equal numbers. In the proximal 

 portion of the arms the pinnules on either side typically alternate, grooved and 

 ungrooved; further out there are 2 grooved pinnules between adjacent ungrooved 

 pinnules, and toward the arm tips all the pinnules are grooved. 



There is a very great difference in the structure of the grooved and ungrooved 

 pinnules, which is well shown in the more proximal portion of the arm where the two 

 types regularly alternate. The grooved pinnules, after the first 2 segments, which 

 are rather large, are slender, dehcate, and very flexible. The ungrooved pinnules 

 have slightly larger basal segments than the grooved and taper veiy gradually, so 

 that they are much stouter than the delicate grooved pinnules. At first the ungrooved 

 pinnules he horizontally, but in the distal half or third of the arms they curve dorsally 

 into the form of a hook or spiral exactly as do the cirri, forming tendrU-hke attach- 

 ments all along the arm, whereby the animal fixes each arm securely to the organisms 

 on the sea floor in addition to fixing its central portion by means of its cirri. 



The segments of the stout grooveless pinnules are produced dorsally into blunt 

 rounded processes exactly resembling the dorsal convex swellings on the outer cirrus 

 segments. These are perfectly smooth, with no trace of spines. These processes are 

 entirely absent from the slender grooved pinnules which, instead, bear on the dorsal 

 side of the terminal segments the long recurved spines characteristic of the pinnules of 

 all the comasterids. 



The color in life was purplish red, the centrodorsal and first 7 segments of the 

 cirri darker and more brownish, the distal portion of the cirri bright red. 



A dry specimen in the Leyden Museum recorded and described by Hartlaub has 

 the centrodorsal rather thick discoidal with the circular dorsal pole slightly convex 

 and about 6 mm. in diameter. The cirri are arranged in a single marginal row. 



The cirri are apparently XV, 30-40 + . 



The single arm which is preserved entire is 50 mm. long. 



P] and Pa are 10 mm. long and are composed of about 25 short segments, of 

 which the 11 last are involved in the formation of the comb. The carination of the 

 proximal segments of P2 and Pb which is characteristic of Comatula Solaris is lacking. 



Hartlaub remarked that this individual in its general appearance closely re- 

 sembles Comatula Solaris, from which it differs in the much greater number of cirrus 

 segments and the lesser number of segments in the proximal pinnules. 



In the Paris Museum I have examined 2 smaU specimens without locality, but 

 collected by Quoy and Gaimard. The larger has an arm length of only about 35 mm. 

 The cirri are XII, 29-30. 



In the British Museum I examined a remarkably fine specimen from Port Phillip, 

 Victoria. 



Abnormality. — In the specimen probably from Perth, on one arm, the right 

 derivative from the left anterior ray as viewed from the ventral surface, the ambula- 

 cral grooves of 2 succeeding pinnules on the same side of the arm arise from the same 

 point on the brachial ambulacral groove. 



Localities. — ?Vicinity of Perth, Western AustraUa; Hamburg southwest Austra- 

 lian E.xpedition, 1905 [A. H. Clark, 1911] (1, H. M.). PI. 31, figs. 93, 94. 



