318 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



that they are united by a syzygium, as Miiller describes, and as is the case with 

 the second and third radials of Act. Solaris, while I was equally unable to deter- 

 mine a syzygial union between the two segments of which the distichal series is 

 composed. Lamarck's original specimen of this species in the Paris Museum 

 is wrongly labelled C. brevicirra, Troschel. 



The specimens to which he referred are 3 small examples of Comanthus parvi- 

 cirra which had been brought from Australia by Pe"ron and Lesueur, and he quite 

 overlooked Lamarck's specimens of Comatula rotalaria which I found in 1910. 



When the comatulids of the Challenger expedition were submitted to him for 

 study by Sir Wyville Thomson in 1878, Carpenter found among them a very consid- 

 erable number of specimens of this species. In looking over the collection in the 

 British Museum he found others which had been dredged by Prof. J. Beete Jukes 

 and also by the Alert in the northeast Australian region. These did not conform 

 with the characters of Comatula rotalaria as given in his notes taken from what he 

 supposed were they type specimens, and he therefore assumed that they represented a 

 new species, which he called in his preliminary notice of the Challenger collection in 

 1879 Actinometra jukesii. 



While at the British Museum he had told Professor Bell of this new form and 

 had identified for him the specimens of it in the museum's collection. 



In 1882 Bell, in his list of specific formulas for the various species of comatulids, 

 mentioned Actinometra jukesi without comment, and gave a specific formula for 

 another form from the Alert collection which he called Actinometra paucicirra. 



In 1883 Carpenter published a specific formula for Actinometra jukesi and an 

 emended formula for Actinometra paucicirra. 



In 1884 Bell listed Actinometra jukesi from two localities where it had been 

 dredged by the Alert, mentioning that it was a new species which would shortly be 

 described by Carpenter, and described Actinometra paucicirra in detail. 



In the Challenger report on the stalked crinoids (1884) Carpenter made frequent 

 mention of Actinometra jukesi. He noted that it was common at Cape York, where 

 isolated disks as well as complete individuals were dredged by the Challenger, that 

 the mouth is radial and the disk, especially the anal area, is more or less beset with 

 calcareous nodules, and that a parasitic isopod of the genus Anilocra (see vol. 1, pt. 2, 

 p. 632), nearly half an inch long, is sometimes found in the anal tube. He described 

 the transformation of the centrodorsal from the cirrus bearing form in the young to 

 the sunken plate of the adult, and gave a specific formula both for the adult and for 

 the young. He cited this species as typical of the Actinometra jukesi group of the 

 genus Actinometra, which he characterized by the occurrence of IIBr 2 (1+2) series, 

 and figured a disk showing the radial position of the mouth, a heavily plated anal 

 area, and an isopod within the anal opening. 



In 1885 Professor Bell recorded Actinometra jukesi from Port Molle, Queensland. 

 In 1888 Carpenter described in detail the specimens which had been collected 

 by the Challenger. For these he used the name Actinometra paucicirra, as he had 

 found that Bell's Actinometra paucicirra, of which a specific formula had been pub- 

 lished in 1882 and which had been described in detail in 1884, was simply an immature 



