Ki-liinodeniia II: Criiioidea. 313 



The other grou}) is eouipuscd ol" miieh smallor torms, all of which 

 agree in having a dorsal carination on the arms ; this group includes live 

 species Avhich, witli tlioir respective ranges, are as foUows : Tropiometra 

 picta: East coast of South America from St. Liicia in the Lesser Antilles 

 and Venezuela south to Santa Catharina Island in southern Brazil (28" S. 

 lat.), and eastward to St. Helena. — T. carinaia: South Africa, northward to 

 Zanzibar, also occurring ab out Madagascar and the Seyclielles, and gene- 

 rally among the islands of the southwestern Indian Ocean. — T. audouini: 

 Red Sea. — T. indica: Ceylon and the adjacent portion of southern India. — 

 T. encrinus: known from „V India", „East Indies" and „Eastern Asia". — 

 A speeies, undetermiued, has also been recorded from „?Fiji," and from 

 the „VKingsmill (<", e., Gilbert) Islands." 



In the present connection the item of interest is the occurrence, 

 commonly, at St. Helena of the same speeies which is found abundantly 

 along the east coast of South America, and the existence of a different, 

 though related, form, which is similarly abundant, in south and south- 

 eastern Africa. 



The Genus Antedon. 



The genus Antedon has remained the chief unsolved puzzle with. 

 which the Student of the recent crinoids has to deal. Only a single attempt 

 has been made at its Solution, and this was more a confession of defeat 

 than a step in advance. Just before he died P. H. Carpenter suggested 

 that all of the speeies of the genus in reality represent but a single speci- 

 fic type. 



The ränge of the genus is : Throughout the Mediterranean Sea; both 

 coasts of the Atlantic, in the east from Norway to the Gulf of Guinea, 

 and in the west from St. Thomas in the Danish West Indies south to 

 Rio Janeiro. 



In the east we find a number of genera which are closely related to 

 Antedon, none of which extend further to the westward than the Bay of 

 Bengal. Two of these deserve special mention as being but very slightly 

 differentiated from the European type. These are, Mastigometra (with two 

 speeies) occurring at Ceylon and in the East Indies, and Euantedon 

 (with four speeies) occurring on the Chinese coast, in the Moluccas, and 

 at Tahiti. 



The fact that all of the close relatives of Antedon are confined to 

 the region east of the Bay of Bengal except one which only ranges to 

 Ceylon, just as Psathy r ome.tr a, the dosest relative of Leptometra, the other 



