W. T. CALMAN. 



serrated on its lower edge. Anteimules with the inner ramus of considerable size, 

 longer than the first segment of outer ramus. Uropods a little longer than the last 

 two somites together, peduncle shorter than the subequal rami and having five spines 

 on its inner edge. Endopod with ten spines on its inner edge, without setae on its 

 outer edge, the proximal segment twice the length of the distal. 



FIG. 1. Leucon australis, ADULT FEMALE, FROM THE SIDE, APPENDAGES OMITTED. 



Occurrence. W.Q., June 15, 1902. D-net. 



Remarks. Among the thirteen species at present referred to the genus Lsucon, 

 four have the inner ramus of the antemmle of considerable size, at least equal in 

 length to the first segment of the outer. Of these, L. longirostris, Sars, L. 

 tenuirostris, Sars, and L. sipltonatus, Caiman, have the antennal notch narrow and the 



FIG. 2. Leucon australis, CARAPACE AND ANTENNTJLE. 



FIG. 3. Leucon australis, LAST SOMITE AXD UIIOPOD. 



antero-lateral margin serrated a"bove the notch. L. septemdentatus, Zimmer, from 

 Tierra del Fuego, resembles the present species in the form of the antennal notch, but 

 differs in the truncate pseudorostrum, in having the serrations of the dorsal crest 

 confined to its anterior part, and the distal segment of the inner ramus of the uropods 

 much less than half the length of the proximal segment. 



