No. 398.] MWORTH-AMERICAN INVERTEBRATES. 135 
C. Antero-lateral margin continued to the angle of the buccal 
cavity. Carapace eroded . os. yptoxanthus 
Cc’. Antero-lateral margin ending at he orbit. 
D. A deep notch in the anterior border of the merus of the 
external maxillipeds. Carapace nodose . .  Daira 
D’. No deep notch in the anterior border of the merus of the 
external maxillipeds. Carapace not nodose 
cloxanthops 
B. Fronto-orbital border half or more than half the greatest width of 
the carapace. 
C. Chelipeds with a circular cavity on the anterior margin between 
the carpus and manus . . . . Carpoporus 
C. Chelipeds without a circular TECUM on the anterior margin. 
D. Carpal joints of ambulatory M armed above with a 
horned or lunate crest . , ."'Hetmcues 
D’. Carpal joints of ambulatory igsi not pee with a horned 
crest. 
E. Carapace tresevecir oval. 
F. Ambulatory legs spiny or ud on the upper 
border Xanthias 
FK Abols beri not eee nor iioii on the 
upper border. 
G. Four or more well-marked antero-lateral 
teeth, excluding the orbi 
Leptodius 
G’. Four antero-lateral teeth (besides the or- 
: bital), the first of which is low and more 
or less fused with the orbital 
urypanopeus 
E'. Carapace more or less hexagonal or subquadrate. 
F. Carpal and propodal joints of ambulatory legs 
more or less cristate. . .  Lophopanopeus 
F*. Carpal and propodal joints of ambulatory legs 
not cristate. 
G. Ambulatory legs spinulous. pip erat 
G’. Ambulatory legs not spinulous. 
H. Three antero-lateral teeth besides the 
orbital, the second normal tooth, or 
that next the orbital, being obsolete 
Glyptoplax 
LP. Four antero-lateral teeth besides the 
orbital, the second normal tooth, or 
that next the orbital, being some- 
times partially united with the or- 
bital, but never obsolete. 
