REPORT ON THE ASTEROIDEA. 383 



Chorology of the Genus Ganeria. 



a. Geographical distribution : — 



Atlantic : One species between the parallels of 45° and 55° S. 



Ganeria falklandica, from the Falkland Islands, and off Cape 

 Virgins, near the Atlantic entrance to the Strait of Magellan. 



/3. Bathymetrical range : 55 fathoms. 



•y. Nature of the Sea-bottom : Sand. 



Cliorological Synopsis of the Species. 



1. Ganeria falklandica, Gray (PI. LX. figs. 1 and 2 ; PI. LXII. figs. 6 and 7). 

 Ganeria falklandica, Gray, 1847, Proc. ZooL Soc. Lond., Part xv. p. 83. 



Locality. — Station 313. Off Cape Virgins, east coast of South America, near the 

 Atlantic entrance to the Strait of Magellan. January 20, 1876. Lat. 52° 20' 0" S., 

 long. 67° 39' 0" W. Depth 55 fathoms. Sand. Bottom temperature, 47°'8 Fahr. ; 

 surface temperature, 48 0, 2 Fahr. 



Remarks. — A considerable amount of variation occurs in the number of the spinelets 

 on the abactinal plates, in the manner in which these are grouped, and in the extent and 

 character of their membranous investment. In medium-sized examples there are as a rule 

 comparatively few granuliform spinelets, on the outer part of the ray not more than two 

 or three being near together ; and the membrane only mounting their bases causes them 

 to appear very short and conical. Furthermore, in small and medium-sized specimens the 

 marginal plates have only a single vertical series of spinelets, excepting a few plates in the 

 interbrachial arc, whereas in large examples the series is doubled ; the disposition of the 

 additional spinelets being subject, however, to considerable irregularity. In the examples 

 collected by the Challenger the actinal intermediate plates usually bear one spine, and 

 occasionally two or three — the latter number very rarely. 



An interesting feature in this starfish, which appears to have escaped notice in the 

 descriptions of Gray and Perrier, 1 is the presence of a more or less clearly defined broad 

 medio-radial band, which is most distinct on the outer half of the ray, although in some 

 1 R6vis. Stell. Mus., p. 327 (Archives de Zool. exper., 1876, t v. p. 247). 



