A MONOGRAPH OF THE EXISTING CRINOIDS 271 



Geographical range. From Mindoro, Philippine Islands, southward to Bowen, 

 Queensland, and to between Fremantle and Geraldton, Western Australia. 



Bathymetrical range. From the shore line down to 110 (?146) meters. 



Occurrence. Dr. Hubert Lyman Clark said that the three individuals of this 

 species that he found at Mer in the Murray Islands were all found among the staghorn 

 corals of the extreme margin of the southwestern reef, a region accessible only at the 

 lowest tides. They attracted attention by their very dark color, their extreme rigid- 

 ity, and their inertness. Unlike the other comatulids watched under their natural 

 conditions, these were erect and apparently rigid, firmly attached by the numerous 

 long stout cirri to a branch of coral. There was no graceful movement of the arms, 

 nor did they sway freely back and forth in the currents of water as did those of the 

 large dark-colored Comanthus (timorensis) near by. In pail or basin at the laboratory 

 afra remained most inert, making no effort to move and showing no response to 

 mechanical stimuli. 



History. Dr. Clemens Hartlaub in 1890 first described this species under the 

 name of Antedon afra from a specimen that had been brought from Bowen, Queens- 

 land, by the Godeffroy Company of Hamburg. Dr. C. F. Liitken had labeled this 

 and another specimen from the same locality Antedon afer, and Hartlaub simply 

 adopted Liitken's name. Hartlaub redescribed and figured the species in 1891. 

 He said that this species belongs to the group of species of Antedon in which, as in 

 A. milberti, there is no marked difference in length between P 2 and P 3 . It is a very 

 striking form because of its plump and massive build. Especially noteworthy are 

 the common lack of an opposing spine, the discoidal brachials from which the first 

 two stand out through then' much larger size, and the strikingly abrupt and thread- 

 like attenuation of the pinnules at the distal end of the gonad, which recalls the same 

 feature in Heliometra glacialis. 



In my first revision of the old genus Antedon published in 1907, afra was referred 

 to the new genus Tropiometra. In a paper published on July 15, 1908, I mentioned 

 a dried specimen of this species from the "South Pacific" in the collection of the United 

 States National Museum and said that it agrees in all particulars with the seven 

 specimens described therein from Sagami Bay (macrodiscus) . It has rather more 

 cirrus segments than did Hartlaub's type specimen, these numbering about 33, as 

 given in Hara's description of macrodiscus. In a paper published on August 25, 

 1908, but written in advance of that just mentioned, I said that afra is quite distinct 

 from the Japanese macrodiscus, but that I had been able to examine only one specimen 

 of each. These were the dried specimen of afra from the "South Pacific" and a speci- 

 men of macrodiscus from Misaki recorded in April 1908 by Dr. Hubert Lyman Clark. 

 In 1909 I described hi detail a specimen from Bowen in the Copenhagen Museum 

 that had been brought to Europe by the Godeffroy Company of Hamburg and bore 

 the manuscript name Antedon afer given it by Prof. C. F. Liitken. I also gave notes 

 on the dried specimen from the "South Pacific" previously mentioned, and said that 

 it was intermediate in its characters between Hartlaub's type specimen and the one 

 in the Copenhagen Museum from Bowen, and a specimen from Misaki the one 

 recorded by Dr. H. L. Clark. 



In my memoir on the recent crinoids of Australia published in 1911 I said that 

 afra is a large and stout species with arms usually somewhat over 200 mm. long which 



