166 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



green, or reddish, and sometimes banded or tipped with yellow. 

 Diam, 25 ; alt., 12| mil. Longest spines, 6 to 7. Diam. of 

 actinosome, 10. Diam. of abactinal system, 7. 



Cape Grenville and Darnley Island, on sandy mud, 10 to 20 

 fathoms. 



This species seems to me to differ from E. magellanicus in the 

 actinosome being larger ; in the abactinal system, where the G. 

 plates have only two tubercles, and in the color of spines and 

 test. 



Genus 8. — Hipponoe, Gray, 1841. 



Echini of large size, and thin test. Tubercles small, smooth, 

 imperforate, arranged in horizontal and somewhat irregular 

 vertical rows. Medium A. and I. spaces frequently bare. 

 Actinosome small, deeply notched. Porif. zones broad, in three 

 vertical rows, outer ones regular, middle one irregular. A. area 

 very broad. Spines short, stout, finely striated, not easily 

 falling off. 



Hipponoe variegata, Leske. 



A very variable species, differing very much in various 

 localities in size, shape, and color. The tubercles are very small, 

 the porif. zones somewhat narrow, and the median areas seen 

 from above, form five radiating bands, gradually increasing in 

 width. These are blue or violet in the tropical specimens, which 

 are somewhat conical and small. The Port Jackson specimens 

 are much larger, rounded, depressed, and of a light cream color, but 

 I have seen some from the same locality almost conical, and of 

 deep brown color. It is not given as Australian in Mr. Agassiz's 

 lists. Mr. Macleay obtained it at Cape Grenville, Endeavour 

 River, Darnley Island, and New Guinea. Its habitat is generally 

 tropical. If it were not for the fear of adding to the host of 

 synonyms which this species has obtained, I should consider the 

 large Port Jackson species as a variety to be distinguished as 

 Jacksoniensis. It is found in shallow water, on a sandy bottom. 



