61G THE VOYAGE OF H.M.S. CHALLENGER. 



b. Moutli-spines proper more or less aborted ; when present confined in 

 an attached membranous sac. Abactinal plating rudimentary, 

 microscopic, and not imbricating. Kays ten. Lateral spines 



very long. Ovarial regions very short remex. 



B. Rays less than ten in number. 



a. Rays six in number. Mouth-spines straight and spiniform. 



a. Abactinal plating extending beyond the ovarial region ; each 



plate with a central tubercle only, bearing a spinelet covered 

 with membrane crowded with pedicellariae. One mouth- 

 spine proper .......-•• tubereulata, 



b. Abactinal plating not extending beyond the ovarial region ; 



each plate bearing two or three small spinelets, covered 

 with simple membrane devoid of pedicellariae. One or two 

 mouth-spines proper benthophila. 



b. Rays nine in number. Mouth-spines subcrescent or scimitar-shaped. 



Adambulacral armature with one inner spine. Abactinal plates 



with three to five small spinelets heroina. 



c. Disk and number of rays unknown. Probably nearly allied to the 



preceding species, but the segments of the ray are longer. 

 Adambulacral armature devoid of an inner spine, except at the 

 base of the ray. Abactinal plates with one to three small spinelets . atienuata. 



Chorology of the Genus Freyella. 



a. Geographical distribution : — 



Atlantic : Seven species between the parallels of 50° N. and 10° S. 



Freyella americana, off Nova Scotia. * Freyella bracteata, off 

 the coast of North America, east of New Jersey and Massachusetts, 

 and south of Nova Scotia. Freyella elegans, between Cape Hatteras 

 and Nova Scotia. Freyella spinosa, off the coast of the Soudan. 

 "Freyella tubereulata, between the Canary Islands and Cape Verde 

 Islands, and between the south coast of Africa and the Island of 

 Ascension. Freyella sexradiata, dredged by the " Talisman" (1 loc). 

 Freyella edivardsi, dredged by the " Travailleur " (1 Mediterranean). 

 Southern Ocean : One species between the parallels of 45° and 65° S. 



'"Freyella fragilissima, between Marion Island and the Crozet 

 Islands, and in the neighbourhood of the pack ice near the Antarctic 

 circle. 

 Eastern Archipelago : One species between the parallels of 0° and 20° N. 



*Freyelld echinata, in the Celebes Sea between Celebes and Min- 

 danao, and west of the island of Luzon, and extending into the Pacific. 

 Pacific : Eight species between the parallels of 40° N. and 45° S. 



"•Freyella heroina, in the Mid-North Pacific, near the meridian of 

 1 70° E. * Freyella pennata, off the coast of Japan, south of Kawatsu. 

 '■Freyella attenuata, west of the Mariana or Ladrone Islands. % Frey- 



