A MONOGRAPH OF THE EXISTING CRINOIDS 



97 



further examination. Carpenter pointed out that in Bell's description of Antedon 

 microdiscus he overlooked the syzygy between the elements of the IBr series and also 

 made no mention of any axillaries beyond the IVBr series, although such must be 

 present to bring the number of arms up to 90, the number he describes in the adult 

 while several IVBr series are represented in his figure. Carpenter said that it is the 

 presence of the fourth axillary above the IBr axillary that is one of the characters dis- 

 tinguishing A. microdiscus from A. multiradiata and that he had not seen any specimen 

 without it, though it is much more frequent in the individual from Port Molle than in 

 those from Nicol Bay and Torres Straits. Carpenter said that these last resemble one 

 another in having a smaller number of cirrus segments and a better-developed opposing 

 spine than the type. Carpenter remarked that the segments of the cirrus figured by 

 Bell are much broader than long, whereas in the Challenger specimen this is only the 

 case in the outer part of the cirrus, some of the proximal segments being as long as, or 

 longer than, broad, and in premature cirri the length is distinctly greater than the 

 width, while the opposing spine is especially prominent. Carpenter noted that Bell 

 described the second or palmar pinnule of his type specimen as being a good deal 

 longer than the first Dr distichal one. But he found that this is not the case in the 

 specimen dredged by the Challenger. Furthermore, the pinnules show no trace of the 

 slightly keeled basal segments described by Bell. But the distal edges of the basal 

 segments are somewhat sharp, and beyond the sLxth segment they project slightly 

 over the bases of those succeeding. This feature gradually develops into a blunt 

 slightly spinous process, which is most marked at about the fifteenth segment and dis- 

 appears altogether after the twenty-fifth; but in the palmar pinnule figured by Bell 

 it is not visible until the eighteenth segment and continues until near the end of the 

 pinnule. Carpenter said that it is this feature apparently which led Bell to say that 

 "the more distal joints are provided with a spine or tuft of spines." 



In 1898 Prof. Ludwig Doderlein recorded and gave notes upon a specimen from 

 Thursday Island. 



In 1909 I recorded a specimen that had been dredged by the Gazelle in Mermaid 

 Strait, and in 1911 I recorded two specimens from Shark Bay that had been collected 

 by the Hamburg Southwest Australian Expedition hi 1905, and also others from 

 Lewis Island in the Dampier Archipelago, from Holothuria bank, and from north- 

 western Australia, which I had seen in the British Museum. 



After an examination of the type specimens of Antedon microdiscus and of Antedon 

 multiradiata in the British Museum I, in a memoir on the crinoids of the Hamburg 

 Museum published in 1912, announced that they really represent the same species, 

 I had also examined the type of Hyponome sarsi, which is in the Hamburg Museum. 

 and this I placed, with a query, in the synonymy of Zygometra microdiscus. A speci- 

 men from another locality hi Shark Bay was recorded and described. 



In a paper on the crinoids of the Berlin Museum published in 1912, I listed the 

 specimens of this species hi that institution. These are the two from Shark Bay 

 recorded and described hi 1911, and the Gazelle specimen from Mermaid Strait. 



In a memoir on the crinoids of the British Museum published hi 1913, I gave 

 notes upon the 10 specimens of this species hi its collection and stated that the two 

 specimens that served Carpenter as the types of Antedon multiradiata are simply small 

 examples of the species represented by the type of Bell's Antedon microdiscus. In a 





