A MONOGRAPH OF THE EXISTING CRINOIDS 123 



Port Curtis, Queensland [A. H. Clark, 1911, 1913] (3, U. S. N. M., 35150; Austra- 

 lian Mus.). 



Geographical range. — Aru Islands and the northern coasts of Australia south to 

 Port Curtis, Queensland. 



Bathymetrical range. — Littoral and sublittoral; from the shoreline down to 50 

 meters. 



History. — This species was first mentioned in my monograph of the recent 

 crinoids of Australia, published in 1911, under the name of Heterometra bengalensis. 

 The three small specimens from Port Curtis referred to Heterometra bengalensis 

 represent this species, but the one from Holothuria Bank in the British Museum is in 

 reality an example of Zygometra comata. 



In 1912 Zygometra punctata was described as a new species on the basis of a 

 specimen from Siboga station 273. In 1913 in a supplementary paper on the crinoids 

 of southwestern Australia all of the Australian records of Heterometra bengalensis 

 were referred to this species. 



In a paper on the crinoids in the British Museum published in 1913, Zygometra 

 punctata was recorded from Holothuria Bank. The specimen from Holothuria Bank 

 is in reality, however, Z. comata. It was this specimen that served as the basis for 

 all the records from Holothuria Bank in both earlier and later papers. 



In 1913 Dr. August Reichensperger described a young 10-armed specimen from 

 the Aru Islands. 



In the Siboga report published in 1918 this species was redescribed and figured, 

 and another specimen from station 273 was mentioned. Holothuria Bank was again 

 erroneously included in the range. Dr. Hubert Lyman Clark's Heterometra delicata, 

 based upon a single specimen that he had found on the sand flat on the southern end 

 of Friday Island, Torres Strait, was included in the synonymy of this species. This 

 is an error, as the type specimen of Heterometra delicata is a young specimen of some 

 species of Heterometra. 



ZYGOMETRA PRISTINA A. H. Clark 



Plate 7, Figures 22, 23 



Zygometra prislina A. H. Clark, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 537 (description; Albatross 

 station 5276); Crinoids of the Indian Ocean, 1912, p. 106 (synonymy; habitat). — Reichen- 

 sperger, Abh. Senck. naturf. Ges., vol. 35, Heft 1, 1913, pp. 91, 92 (comparison with Z. 

 mertoni [ = young Z. microdiscus]) . — A. H. Clark, Unstalked crinoids of the Siboga-Exped., 

 1918, p. 60 (in key; range). — Gisl£n, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 

 1934, pp. 17, 18. 



Diagnostic features. — The possession of only 10 arms and the partially developed 

 syzygy between the elements of the IBr series distinguish this species at once from 

 all the others in the genus. The arms are 50 mm. long. The cirri are XII, 20-21, 

 12 mm. long, with the longest segments about one-third again as long as broad. 



Description. — The centrodorsal is low hemispherical with the bare polar area 

 papillose, 1 mm. in diameter. The cirrus sockets are arranged in a single irregular 

 not especially crowded row. 



The cirri are XII, 20-21 , 12 mm. long, and moderately slender. The first segment 

 is short, the following gradually increasing in length and becoming about one-third 

 again as long as broad on the fourth. The next two segments are similar, and those 



