AMrillUiiA. 



115 



Ophiactis sexradia LCtken. 



Ophiolepix srxrndia Oiirni:. Wit'iiinann's Arcliiv., p. 312. I. 1857. 

 Ophiactis sexradia Ll'tkkx. Addit. ad Illst. Oph., 11. p. 12G. 



LIST OF SPECIMENS. 



Catalogue 

 Number. 



Oripinal 

 Number. 



Numbur 



of SlK'C. 



Locality. 



When 

 Collected. 



Whence obtained. 



Nature of 

 Specimen. 



Museum of Comparative Zoology. 



227 

 403 sp. ? 



12-|-j Sandwicli Islands. 

 . . Zanzil)ar. 



A. Garrett. 



Alcoholic. 



AMPHIURA Forbes. 



Type of the Genus, A. Jiliformis. 



Disk small and delicate, covered with naked, overlapping scales, and 

 furnished with uncovered radial shields. Teeth. No tooth-papilhB. 

 Six (rarely eight) mouth-papilh\3 to each angle of the mouth. Arms 

 slender, even, more or less flattened. Arm-spines short and regular, 

 arranged along the sides of the side arm-plates. Two genital slits to 

 each interbrachial space. 



GROUPING OF SPECIES HEREIN DESCRIBED. 



Arms long and slim ; middle arm-spine with a cross-piece at the end, A. JiUformis. 



Arms very slim and of great length (often twenty-four times as long as ) 



diameter of disk), tapering only at their tips ; outer mouth-papilla > A. gracilUina. 



broadest ; radial shields very long and narrow, ) 



One mouth-papilla placed above the rest ; radial shields long and narrow, ■] 



IIolWlL 

 Chi((jii. 



geminata. 



Outer mouth-papilla broadest; under arm-plates pentagonal; arms of, 

 moderate length (about eight times the diameter of the disk). 



Outer mouth-papilla much the broadest; under arm-plates pentagonal ;j 

 side mouth-shields large and meeting within, J 



Under arm-plates broader witliin than without, 



Souie of the disk-scales with toothed edges, 



IMouth-papilhe equal, separated ; under arm-plates scpiare ; upper arm- ) 



plates large, overlapping, wider without than within, with rounded \- A. occidentalis. 



outer corners, ) 



squamata. 



tenera. 



pugetana. 



atra. 



iirtica. 



