A MONOGRAPH OF THE EXISTING CRINOIDS 



561 



close as would be expected in two specimens of the same species. In the type specimen 

 of ajra synarthrial tubercles are not developed, and in the type specimen of multicirra 

 they are low and relatively inconspicuous. 



Remarks. Dichrometra a/ra differs from D. fiagellata, which it represents in the 

 western Indian Ocean, much as Capillaster coccodistoma differs from C. multiradiata. 

 It is smaller and more delicate, with usually fewer arms, and lacks the characteristic 

 rugosity of the arm bases and the prominent synarthrial tubercles. P 2 and P 3 are 

 proportionately less enlarged and more delicate and are not greatly longer than PI. 



Localities. Lainu, Kenya (between Port Durnford and Mombasa) ; reef opposite 

 the harbor; Dr. Alfred Voeltzkow [Ludwig, 1899; A. H. Clark, 191 1]. 



Zanzibar; Dr. Alfred Voeltzkow [Ludwig, 1899; A. H. Clark, 1911, 1912]. 



Zanzibar [A. H. Clark, 1911, 1912, 1913] (2, B. M.). 



Zanzibar; D. Cyril Crossland [A. H. Clark, 1929] (1, B. M.). 



Pieter Faure, 12157; Durnford Point, Zululand, bearing N.W., % W., 12 miles 

 distant; 164 meters; broken shells [H. L. Clark, 1923] (1, South African Mus.). 



Cape St. Andr6, Madagascar; about 30 meters; Dr. P. R. Joly, 1901 [A. H. Clark, 

 1911,1912] (2, P. M.). 



Madagascar; C. Moll [A. H. Clark, 1912] (1, H. M.). 



Geographical range. Coast of east Africa from Lamu, Kenya, southward to Durn- 

 ford Point, Zuzuland, and Madagascar. 



Bathymetrical range. From the shoreline down to 164 meters. 



History. In his memoir on the echinoderms of the Zanzibar region published in 

 1899, Prof. Hubert Ludwig recorded Antedon fiagellata from Lamu and Zanzibar on the 

 basis of three specimens from each locality that had been collected by Dr. Alfred 

 Voeltzkow. 



In a paper on the crinoids of the coasts of Africa published early in 1 9 1 1 , 1 recorded 

 under the heading Dichrometra (?species) two young examples "of some species of 

 Dichrometra" from Cape St. Andr6, Madagascar, in the Paris Museum, and one from 

 Zanzibar in the British Museum. Under the same heading, repeated, I recorded "a 

 young specimen of some species of Dichrometra near D '. fiagellata" from Zanzibar in the 

 British Museum. I also listed Dichrometra fiagellata from Lamu and Zanzibar, on the 

 basis of Ludwig's records. 



In a paper on the crinoids of the Paris Museum published in 1 9 1 1 , 1 recorded under 

 Dichrometra sp. "deux jeunes exemplaires de quelques espece de Dichrometra voisine de 

 D. palmata" from Cape Saint-Andre, Madagascar, that had been collected by Dr. 

 P. R. Joly in 1901 and gave notes on them. These are the two specimens mentioned 

 above. 



In 1912 in a paper on the crinoids of the Hamburg Museum I described Dichro- 

 metra fiagellata var. afra from a specimen from Madagascar that had been collected by 

 C. Moll. In the synonymy of this new variety I included Ludwig's records of Antedon 

 fiagellata from Lamu and Zanzibar and my own records of Dichrometra sp. from Cape 

 St. Andre 1 , Madagascar, and Zanzibar. 



In my memoir on the crinoids of the Indian Ocean published in 1912, I included 

 ?Madagascar and ?Zanzibar in the range of Dichrometra fiagellata and recorded 

 Dichrometra sp. from Madagascar and also from Zanzibar. 



