588 THE AMERICAN NATURALIST. | [Vor. XXXIV. 
KEY TO THE GENERA OF THE FAMILY PINNOTHERID. 
4. Carapace convex. Eyes small. 
B. Ischium of outer maxillipeds rudimentary. 
C. Palpus of outer maxillipeds with three joints. 
D. Last joint of palpus articulated on inner margin of pre- 
ceding joint. 
E. Third ambulatory leg longer and stronger than the 
others, usually considerably so . Pinnixa 
E'. Third ambulatory leg very little, if any, longer than 
the others 
F. Carapace without a longitudinal suture behind 
the orbis . . . . . «; . PI 
EZY 
Fic, 9. Fic. 10. 
Fic. 8. — Pachygrapsus transversus, carapace. 
Fic. 9. — Pachygrapsus transversus, chela. 
Fic. 10. — Hemigrapsus nudus. 
Æ. Carapace with a longitudinal suture behind the 
orbits enclosing between them the median 
area . VU V c. ces atur AMOR 
D’. Last joint of palpus articulated at end of preceding joint 
Echinophilus 
C. Palpus of outer maxillipeds with two joints . Cryptophrys 
B'. Ischium of outer maxillipeds distinctly developed . ^ Opisthopus 
A’. Carapace flat, suborbicular, truncate behind. Eyes large (for the 
family), each eyestalk as long as half the width of the front Zaops 
THE SPECIES OF PINNOTHERID/E. 
Genus Pinnixa White. 
Key to Species. 
A. Carapace firm. 3 
B. Pollex of cheliped distinctly developed. 
C. Pollex much shorter than the dactylus, and usually bent 
downwards toward the extremity. 
. Transverse crest on the cardiac region short, not extend- 
ing across the entire carapace. 
