56 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



with "The most proximal joint the longest," while the figure given shows fourteen 

 segments, the third and fourth decidedly the longest. In view of our imperfect view 

 of adeonae, and the obvious resemblance between that species and both bidens and 

 Ihetidis, it seemed to Dr. Clark quite possible that more abundant material will show 

 that the three names belong to a single species. 



In my report upon the crinoids of the Hamburg Southwest Australian Expedition 

 published in 1911, Oligometra thetidis was given as a tropical species confined to 

 Australia, but known only from Wollongong. 



In my memoir on the crinoids of Australia published in 1911 I listed Oligometra 

 thetidis as one of the seven species of crinoids confined to the southern part of Aus- 

 tralia. Speaking of Australia, I said that here the genus Oligometra from the widely 

 spread serripinna stock produces an entirely distinct species, 0. carpenteri, which, as 

 in the case of the Australian species of Zygometra, is the extreme form of the genus, 

 and from a somewhat different branch (from which 0. thetidis is also derived), 0. 

 adeonae. I remarked that I happened to be in Cambridge, Mass., when Dr. Hubert 

 Lyman Clark received the collections of echinoderms brought together by H. M. 

 C. S. Thetis, and that Dr. Clark had most courteously permitted me to examine the 

 specimens of crinoids therein contained. I noted that this new Oligometra was a 

 form of rather exceptional interest and that I had availed myself of the opportunity 

 for drawing up a careful description of it, which I included. I had examined the type 

 specimens of Lamarck's adeonae in Paris in the preceding year, and said that I could 

 not see any grounds for believing that thetidis might eventually turn out to be adeonae 

 as suggested by Dr. Clark. It is much smaller than that species, and the pinnules 

 could not possibly be described as long, nor are the three or four first the longest. 

 I remarked that in general appearance it is curiously similar to Analcidometra caribbea 

 from the Caribbean Sea; it is of about the same size, the lower pinnules are more or 

 less similar in shape and in proportions, and the genital pinnules are similarly expanded. 



In a paper on a small collection of crinoids from the Indian Ocean published in 

 July 1912, I mentioned Oligometra thetidis in connection with the supposedly related 

 0. marginata (=Iconometra marginata) from Solor Strait. In my memoir on the 

 crinoids of the Indian Ocean published on November 22, 1912, I listed Oligometra 

 thetidis and gave its synonymy and habitat. In my memoir on the crinoids of the 

 Antarctic published in 1915 I included in my list of the crinoids of southern Australia 

 Oligometrides thetidis and gave the habitat. 



In 1916 Dr. Hubert Lyman Clark recorded two specimens of Oligometra thetidis 

 that had been dredged by the Australian Fisheries Investigation steamer Endeavour in 

 Bass Strait. He said that these specimens are uniformly yellowish in alcohol and 

 show no noteworthy peculiarities. 



In 1916 I established the new genus Austrometra with Oligometra thetidis H. L. 

 Clark, 1909, as the genotype, and in 1918 listed Austrometra thetidis as one of the 

 crinoids known from Tasmania. In my report on the unstalked coinoids of the 

 Siboga expedition published in 1918 I included Austrometra in the key to the genera 

 of the family Colobometridae, in a footnote giving Oligometra thetidis H. L. Clark, 

 1909, as the genotype and saying that this genus is known only from southeastern 

 Australia. 



