Boone, Echinodermata, Cruises of "Ara" and "Alva" 113 



Echinoidea 



The three species of Echinoidea contained in the present report 

 were secured respectively by the "Alva" explorations in Floridian 

 waters in 1935 and 1936, where a representative series of Dr. 

 Alexander Agassiz's Cidaris abyssicola was taken. The second 

 Echinoid was obtained by the "Ara" World Cruise in Hawaiian 

 waters, establishing another record for the small urchin, Euci- 

 daris metularia Lamarck, first illustrated by the Dutch naturalist, 

 Dr. Seba, in 1734, from Amboina. The third species was collected 

 by the "Alva" South American Cruise of 1935, in Chilean waters, 

 where seven fine specimens of the fragile Spatangid, Brisaster 

 moseleyi (Agassiz) were dredged. This rare echinoid, first taken 

 by the "Challenger," is here figured in detail for the first time. 



The distribution of these sea urchins is as follows : 



Cidaris abyssicola (A. Agassiz), oif Sand Key Light, Florida, 

 100 fathoms and in 65 fathoms off Sand Key Light, Florida. 



Eucidaris metularia (Lamarck), Kaneohe Bay, Oahu, Hawaii, 

 2 fathoms. 



Brisaster moseleyi (A. Agassiz) , Relonca Inlet, Bahia de Coch- 

 amo, Chile. 



Holothuroidea 



The Holothuroidea of the "Ara" World Cruise are represented 

 by two species, one of which, Pentacta arae Boone, from the 

 Anambas Islands, is new to science and forms an interesting con- 

 nection between existing species of the Cucumariidae. The second 

 species is the comparatively rare Eu/ipta godeffroyi (Semper) 

 from the littoral zone of the Hawaiian Islands. 



The Holothuroidea of the "Alva" World Cruise include the 

 adults of four littoral species, also two larval stages of an unusually 

 interesting SynapHd, taken in 140 fathoms depth in the Flores 

 Straits. These littoral species include : Holothuria impatiens For- 

 skal from Falcon Island, Queensland ; H. arenicola Semper, estab- 

 lishing a second record of this species in Samoan waters; an 

 excellent series, consisting of eleven of Actinopyga mauritatm 

 (Quoy and Gaimard) , all from the coral reef zone of Venus Point 



