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THE VOYAGE OF H.M.S. CHALLENGER. 



The five or six additional species dredged by the " Blake," " Tra- 

 vailleur," and " Talisman " Expeditions, which were mentioned above 

 as probably belonging to this genus, are all from the North-Atlantic 

 area. 



Pacific : One species between the parallels of 10° N. and 10° S. 

 Nymphaster hipunctus, north of Admiralty Island. 



Eastekn Archipelago : One species between the parallels of 20° N. and 20° S. 

 Nymphaster symholicus, off the Philippine Islands, and in the Ara- 

 fura Sea. Nymphaster symholicus, var. breviradiata, in the Banda Sea. 

 j8. Bathymetrical range : 28 to 1525 fathoms. 



Two species, viz., Nymphaster hipunctus and Nymphaster symholicus, are 

 found in the Littoral zone; and two species, viz., Nymphaster basilicus and 

 Nymphaster protentus, are confined to the Abyssal zone. 



Greatest range of one species : Nymphaster symholicus, 28 to 115 fathoms. 

 If the additional North-Atlantic species, which I suppose to belong to this 

 genus, be taken into consideration, the greatest range and greatest depth is 

 attained by the species described as Pentagonaster alexandri, Perrier, which, 

 according to Perrier, extends from 84 to 1930 fathoms. (I have already ex- 

 pressed my doubt as to the original generic reference of this form, under the 

 head of the chorology of the genus Pentagonaster.) The form described as 

 Dorigona arenata, Perrier, extends from 164 to 893 fathoms. 

 y. Nature of the Sea-bottom: Each of the species dredged by the Challenger was 

 found inhabiting ground of a different nature. The two deep-water forms, 

 Nymphaster basilicus and Nymphaster protentus, were on Eed mud and Hard 

 ground respectively. Nymphaster hipunctus occurred on Coral mud, and 

 Nymphaster symholicus on Green mud, the variety of the latter — Nymphaster 

 symholicus var. breviradiata — living on Blue mud. 



Chorological Synopsis of the Species. 



