26 THE VOYAGE OF H.M.S. CHALLENGER. 
this last species I offer the suggestion with much doubt, for the description given is alto- 
gether inadequate for classificatory purposes. Iam unable to recognise any of these forms 
amongst the Challenger material. 
Of the several new species from the North-American coast described by Verrill during 
the last few years under the generic name of Archaster, none appear to belong to the 
genus Pontaster. I would, however, suggest that the Asterid from this region which 
has been referred to Archaster tenuispinus may perhaps be found to be the same as the 
form I have named Pontaster hebitus. 
Chorology of the Genus Pontaster. 
a, Geographical distribution :-— 
ATLANTIC : Six species between the parallels of 80° N. and 40° S. 
Pontaster forcipatus and Pontaster hebitus, off the coast of North 
America. Pontaster limbatusin the Faerée Channel, off the west coast 
of Ireland and 8.W. of the Scilly Islands. Pontaster tenuispinus in 
the Faerée Channel, off the Scandinavian coasts, and as far north as 
Spitzbergen. (Also Greenland fide Liitken, and North America fide 
Verrill.) Pontaster tenwispinus, var. platynota, in the Faerée Channel 
and off the west coast of Ireland. Pontaster venustus, east of the 
Azores, and Pontaster venustus, var. robusta, off the Cape Verde Islands. 
Pontaster pristinus, off the eastern coast of South America. 
Paciric: Four species between the parallels of 40° N. and 50° 8. 
Pontaster oxyacanthus, south of Japan. Pontaster trullipes, west 
of the island of Luzon (Philippines). Pontaster subtuberculatus, east 
of Australia. Pontaster planeta, west of South America, near the 
entrance to the Straits of Magellan. 
HASTERN ARCHIPELAGO: Two species between the parallels of 0° and 10° S. 
Pontaster mimicus in the Arafura Sea. Pontaster teres, in the 
Banda Sea, between the Ki Islands and Banda Islands. 
SourHerN Ocean: One species between the parallels of 40° and 50° S. 
Pontaster forcipatus, var. echinata, between Marion Island and the 
Crozet Islands. 
8. Bathymetrical range: 70 fathoms to 2650 fathoms. 
Six species are found above the Abyssal zone (2.e., in depths less than 500 
fathoms), viz., Pontaster hebitus, Pontaster limbatus, Pontaster oxyacanthus, 
Pontaster planeta, Pontaster tenuispinus, with its var. platynota, and Pontaster 
