A MONOGRAPH OF THE EXISTING CRINOIDS 77 



interest brought to light by the study of a small collection of crinoids made by the 

 Investigator is the discovery of a new species of Oligometra allied to the Australian 

 0. adeonae in the Andaman Islands. I said that up to a few weeks before 0. adeonae 

 in north Australia and the Aru Islands and 0. thetidis in New South Wales were 

 supposed to represent a somewhat anomalous type of the genus peculiar to Australia ; 

 but very recently a related species, 0. marginata, had been described from Solor 

 Strait in the Lesser Sunda Islands, where it was dredged bj^ the Dutch steamer 

 Siboga. I said that not only does this new species greatly increase the known geo- 

 graphical range of this curious group, but it possesses an additional interest in being 

 intermediate in its characters between this group within the genus Oligometra and the 

 species of the genus Prometra, furnishing new evidence of the very close interrelation- 

 ships between all the genera comprised within the family Colobometridae. In 

 another paper published in 1912 I compared the cirri of Oligometra adeonae with those 

 of Comantheria weheri, and in still another I compared my new species Oligometra 

 marginata with 0. adeonae. 



In 1913 Dr. August Rcichensperger recorded and gave notes on eight specimens 

 of Oligometra adeonae from four localities in the Aru Islands, and in the same year I 

 recorded four specimens of Oligometrides adeonae from four different localities which 

 I had studied in the British Museum, including the type of Bell's Antedon bidens 

 and the specimen recorded by Bell as Antedon pinnijormis, and gave detailed notes 

 on a specimen from Alert station 87. In 1915 I again discussed in detail the distri- 

 bution of Oligometrides adeonae on the Australian coasts. In my report on the un- 

 stalked crinoids of the Siboga expedition published in 19181 gave a detailed synonymy 

 of Oligometrides adeonae, including under this species Bell's Antedon bidens, Bell's 

 specimen from Dundas Strait recorded as Antedon pinniformis, my own Oligometra 

 marginata described in 1912, and Dr. H. L. Clark's Oligometra anisa. I recorded and 

 gave notes upon eight specimens from station 273 in the Aru Islands, and one, the 

 type of Oligometra marginata, from station 305. 



Dr. Torsten Gisl^n in 1919 recorded and gave detailed notes upon fifteen speci- 

 mens of Oligometra adeonae that had been collected by Dr. Eric Mjoberg in north- 

 western Australia, and discussed the species at considerable length. He named a 

 new form, scabra, giving a brief mention of its distinctive features. 



Dr. Hubert Lyman Clark in 1921 noted that he had failed to find Oligometrides 

 adeonae in Torres Strait but had been able to examine some specimens from the 

 Aru Islands lent him by me, and discussed the history and distribution of the species 

 in detail. In 1924 Dr. Gisl^u described at length various structural peculiarities 

 of this species. In 1938 Dr. Clark gave an account of this species as it occurs at 

 Broome, with brief notes on 61 specimens that he had collected at False Cape 

 Bossut and at Broome. He said that he did not find adeonae at Darwin or at Cape 

 Leveque, perhaps because the local conditions there are unfavorable. 



Genus ANALCIDOMETRA A. H. Clark 



Antedon (part) PouRTALfes, Bull. Mus. Comp. Zool., vol. 1, No. 11, 1869, p. 356, and following 



authors. 

 Tenella group (part) P. H. Carpenter, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 376.— 



Hartlaub, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 394. 

 Oligometra (part) A. H. Clark, Proo. Biol. Soo. Washington, vol. 21, 1908, p. 126. 



