A MONOGRAPH OF THE EXISTING CRINOIDS 



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(under various generic names) from the Indian Ocean region, and the correct deter- 

 mination of the specimens upon which they were based. A synonymy of Tropiometra 

 carinata was given, including lAlecto carinata Leach, Comatula bicolor Dujardin and 

 Hupe", Actinometra Solaris von Martens, and Antedon capensis Bell. The habitat was 

 given as southern and southeastern Africa, including Madagascar, Mauritius, the 

 Seychelles, Reunion, the Mascarene Islands, Saya de Malha, Cargados Carajos, 

 Farquhar Atoll, and Zanzibar. The bathymetrical range was given as littoral and 

 down to 30 fathoms. I noted that Antedon carinata as understood by Carpenter in 

 the Challenger report (1888) was made up of Tropiometra carinata, T. encrinus, and 

 T. picta. I said that although the genus Tropiometra is almost everywhere confined 

 to very shallow water, in the Lesser Antilles the local species (T. picta) is found only 

 at very considerable depths, and, as the same is true of another widely different littoral 

 species in the same region (Nemaster lineata [-N. rubiginosa]) we seem to have evi- 

 dence suggesting that those islands have gradually subsided, carrying these two littoral 

 species down to a level which, though once the coast line, is now more than 100 fathoms 

 beneath the surface. 



In a paper on the crinoids of the British Museum published in 1913, I recorded 

 two specimens of Tropiometra carinata from Mauritius, seven from Zanzibar, and 38 

 from 11 localities in South Africa, these last having previously been determined as 

 Antedon capensis by Prof. F. Jeffrey Bell. I also recorded five lots of specimens of 

 Tropiometra picta from Brazil, one from St. Helena, and two without locality. In my 

 account of the crinoids of west Africa published in 1914 I said that Tropiometra 

 carinata occurs in South Africa and northward to Zanzibar, and also about Mada- 

 gascar and the Seychelles, and generally among the islands of the southwestern Indian 

 Ocean. I said that another species, T. picta, occurs at St. Helena and along the 

 American coast from St. Lucia in the West Indies and Venezuela southward to Santa 

 Catharina Island in southern Brazil. In 1915 in my memoir on the crinoids of the 

 Antarctic I recorded and gave notes on a small immature specimen of Tropiometra 

 carinata from Simons Bay and compared it with the young specimen from Bahia 

 that had been described and figured by Carpenter under the name Antedon dubeni. 

 I said that T. carinata occurs from Simonstown, False Bay, eastward and northward 

 to Zanzibar, and further eastward to Madagascar, Farquhar Island, the Seychelles, 

 Saya de Malha, Cargados Carajos, and Mauritius, in 0-54 meters (0-30 fathoms). 



In 1916 Dr. Hubert Lyman Clark published a preliminary notice of a detailed 

 study of the habits and reactions of Tropiometra carinata which he had found living in 

 shallow water in Buccoo Bay, Tobago, where it was common and easily accessible, 

 in the spring of the same year. At the same time Dr. Th. Mortensen made extensive 

 studies on the development of various echinoderms, including the same species. In 

 1917 Dr. Clark described the habits and reactions of T. carinata in detail. He said 

 that comparison between the comatulids taken at Tobago and a considerable series of 

 specimens from several stations on the Brazilian coast south of the Amazon shows that 

 they are unquestionably identical. He noted that for this Brazilian species I had 

 revived an old name of Gay's, picta, regarding it as "a perfectly good species," "most 

 obviously differing from carinata. in the greater length of the outer cirrus segments." 

 He said that on comparing the Brazilian and Tobagoan material with specimens from 

 Mauritius and Zanzibar he was utterly unable to detect any differences, either in the 



