A MONOGRAPH OF THE EXISTING CRINOIDS 281 



longer brachials. A glance at the cirri alone is sufficient to distinguish them. At 

 the time this was written, in Hamburg, I had before me Hartlaub's type specimen 

 of afra as well as the two specimens of macrodiscus. In my account of the crinoids 

 of west Africa published in 1914 I maintained macrodiscus as distinct from afra. 

 In my report upon the uustalked crinoids of the Siboga expedition published in 1918, 

 I listed Tropiometra macrodiscus as the Japanese representative of the southern T. 

 afra, and in the key to the species of Tropiometra gave its habitat as southern Japan. 



Dr. Th. Mortensen in 1920 said that at Misaki Tropiometra macrodiscus is com- 

 mon in the same localities as the large Comanthus. 



In 1922 Dr. Torsten Gisle'n gave detailed notes upon nine specimens from Misaki 

 that had been collected by Dr. Sixten Bock in 1914. These he recorded under the 

 name Tropiometra afra var. macrodiscus. Citing me, he wrote that macrodiscus 

 differs from T. afra in its longer and stouter cirri, which have more numerous seg- 

 ments. This difference is also to be found in those that were brought home by Dr. 

 Bock's expedition. Nevertheless he cannot consider that a form that differs only in 

 a characteristic of such a low systematic value as this is to be counted as more than 

 a variety. Besides, one must bear in mind, according to Dr. Gisle'n, that T, macro- 

 discus is only known from Sagami Bay [it was at the time also recorded from the 

 Korean Straits], while T. ajra is known from the coasts of Africa [there are no African 

 records; he was probably led astray by the name], Australia, and New Guinea. 

 Therefore it is very probable that transition forms may be brought home from the 

 intervening territory. He asks the reader to compare my descriptions of specimens 

 from Sagami Bay, which are not very different from T. afra. Accordingly he is of 

 the opinion that the differences between macrodiscus and afra cannot be given more 

 than the value of those of a variety. With this conclusion I am in complete accord. 



Under the name Tropiometra encrinus Dr. Gisle'n hi 1922 described a specimen 

 from the Bonin Islands that appears to be a young individual of the present form. 

 He says that the proximal portions of the arms are smooth and a little flattened, which 

 applies to macrodiscus but not to encrinus in which the earlier brachials are roundedly 

 carinate. Tropiometra encrinus is not definitely known from farther east than Java. 

 In 1924 Dr. Gisle'n described various structural features of the arms and pinnules of 

 this form. In 1927 he recorded and gave notes upon three specimens that had been 

 collected by Dr. Th. Mortensen at Misaki. 



In 1934 Dr. Th. Mortensen included Tropiometra afra in a list of the echinoderms 

 of Hong Kong, the identification having been made for him by Dr. Torsten Gisle'n. 

 He gave figures of two specimens from this locality. 



TROPIOMETEA CARINATA CLARKI Gisln 



PLATE 34, FIGURES 175-179; PLATE 35, FIGURES 180-182 

 [See also vol. 1, pt. 2, figs. 60, 61 (radial pentagon), p. 33.] 



Antedon carinata (part) P. H. CARPENTER, Notes Leyden Mus., vol. 3, 1881, p. 179 (Indian Ocean; 

 notes); Journ. Linn. Soc. (Zool.), vol. 16, 1882, p. 502 (Java; characters of the pinnules); 

 Challenger Reports, Zoology, vol. 11, pt. 32, 1884, p. 137 (Java) ; vol. 26, pt. 60, 1888, pp. 200, 202 

 (Java). BELL, Proc. Zool. Soc. London, 1888, p. 387 (Sea of Bengal). HARTLAUB, Mem. Mus. 

 Comp. Zool., vol. 27, No. 4, 1912, p. 371 (?Java). 



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