324 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



D. Lunulas about twice as long as wide ; test thick 

 and heavy, the margins a couple of millimeters 

 or more in thickness. 

 E. Test large, up to 150 mm h. d. ; unpaired 



lunule usually longer than posterior pair, , 



its anterior end a little in advance of the ' 



other two; test high, flattened between 



tip of anterior petal and the posterior 



lunule, highest point may be determinable 



as in middle or at either end ; normal color 



light brown above, with disk and lunule ^ 



margins purple .... galapagensis 



EE. Test smaller; unpaired lunule about the 

 same size and about in line with posterior 

 lunules. Color dark gray or blackish. 

 Test flattened on top, commonly irregu- 

 lar in outline, its greatest height about 

 one-sixth or one-seventh of length; lun- 

 ules relatively small and narrow, the pos- 

 terior three nearly in line . . irregularis 

 Test more curved on top, oval or broadly 

 oval ; its height about one-tenth of length ; 

 lunules long and narrow, the anterior trio 

 slightly smaller .... ecuadorensis 



DD. Lunules 3 to 4 times as long as wide ; test thin 

 and light with relatively thin edges. 

 Unpaired lunule wider than other lunules; 

 its anterior tip little or not at all in front of the 

 posterior pair ...... fragilis 



Unpaired lunule long and narrow, its anterior 

 end well in advance of the posterior pair . 

 insularis 



In this key Clark, according to his views did not include the species 

 grandis. It is easily distinguished from the rest of the species by its margin 

 being thicker, some 5 mm or even more. Th. Mortensen 



