A MONOGRAPH OF THE EXISTING CRINOIDS 317 



Alert; Prince of Wales Channel, Torres Straits; 12.8 meters [Bell, 1884; P. H. 

 Carpenter, 1888; A. H. Clark, 1913] (1, B. M.). 



Alert; Albany Island, Queensland; 5.5-7.3 meters [Bell, 1884; P. H. Carpenter, 

 1888; A. H. Clark, 1913] (1, B. M.). 



Albany Passage [A. H. Clark, 1911] (2, U.S.N.M., 34928; Austr. M.). PI. 32, 

 fig. 98. 



Cape York; Prof. J. Beete Jukes; H. M. S. Fly, 1843-1847 [P. H. Carpenter, 

 1879, 1888; A. H. Clark, 1913] (1, B. M.). 



Challenger; channel between Albany Island and Somerset, Cape York; 14.6-21.9 

 meters; September 7, 1874 [P. H. Carpenter, 1887, 1888]. 



Alert; Torres Straits, 7.3 meters [A. H. Clark, 1913] (2, B. M.). 



Port Molle, Queensland [Bell, 1885; A. H. Clark, 1911] (2, Austr. M.). 



Siboga station 273; anchorage off Pulu Jedan, east coast of the Aru Islands; 

 pearl banks; 13 meters; sand and shells; December 23-26, 1899 [A. H. Clark, 1918] 

 (1 adult and 5 young, U.S.N.M., E. 443; Amsterdam Mus.). 



Challenger; Aru Islands; 1874 [P. H. Carpenter, 1888; A. H. Clark, 1913] (1 + , 

 B. M.). 



Australian Seas [Lamarck, 1816; J. Muller, 1849; Dujardin and Hup6, 1862; 

 P. H. Carpenter, 1879, 1888; A. H. Clark, 1911] (2, P. M.). 



No locality [A. H. Clark, 1913] (1, B. M.). 



Geographical range. From Baudin Island, Western Australia (lat. 14 08' S.), 

 and Port Molle, Queensland (lat. 20 30' S.), to the Aru Islands. 



Bathymetrical range. Littoral, and down to 69.4 meters; the average of 11 

 definite records is 20.2 meters. 



History. This species was originally described as Comatula rotalaria by Lamarck 

 in 1816. In 1843, under the name of Alecto rotalaria, it was carefully redescribed by 

 Miiller from notes made for him on the type specimens in the Paris Museum by 

 Troschel. In 1862 Miiller's redescription was republished by Dujardin and Hupe". 



In his memoir on the genus Actinometra (1879) Carpenter mentioned three 

 comatulids in the Challenger collection having an anomalous arm structure. He said 

 that in two of them the first and second distichals and the first and second brachials 

 are united by syzygies, like the second and third radials; that is, the IBr and IIBr 

 series are 2 (1 + 2). These are the forms which at that time he called Actinometra 

 jukesii and Act. aruensis, later (1888) uniting them under the name of Actinometra 

 paucicirra Bell. 



In 1879 Dr. P. H. Carpenter published the notes on the type specimens of 

 Comatula rotalaria which he had made during a visit to the Paris Museum in 1876. 

 He said: 



According to Muller there are only two radials in Act. rotalaria which are 



united by a syzygium, while they bear the distichal axillaries directly; and 



these are also syzygial segments. Although, like Muller, I examined Lamarck's 



original specimen of this species, I cannot confirm the above statement. It is 



true that only two radials are visible externally ; but this is often the case in Coma- 



tulae, with a wide centrodorsal piece; and I was quite unable to satisfy myself 



