290 AGIDA. 
lowing joints of the pleon are large and broad, the 
posterior lateral angles being produced into a curved and 
acute point,—we shall be convinced that Rocinela Danmo- 
niensis is the type of a distinct genus, and that Aga 
monophthalma of Johnston, which M. Milne Edwards, 
followed by Mr. A. White, introduces into the genus 
Rocinela on account of the large size of the eyes, ought to 
be referred to the genus #ga. ‘This opinion is confirmed 
by the descriptions of the mouth-organs given by M. Milne 
Edwards in the Crochard edition of the “ Régne Animal” 
of the species which he terms Rocinela ophthalmica (giving 
erroneously Leach as the author of the species), which 
prove that that species is in fact an Aiga, differing only 
from Aga emarginata in the apparent soldering together 
of the two terminal joints of the foot-jaws. 
