SYNOPSIS 
OF THE 
GENERA OF NORTH AMERICAN CRUSTACEA HITHERTO OBSERVED. 
I. DECAPODA. 
Libinia, Leptopodia, Hyas, Mithrax, Xantho, Panopeus, Platycarcinus, Pilumnus, Carcinus, Platy- 
onichus, Lupa, Pinnotheres, Ocypoda, Gelasimus, Sesarma, Nautilograpsus, Plagusia, Ilia; 
Hepatus, Lithodes, Hippa, Pagurus, Porcellana, Monolepis, Callianassa, Astacus, Homarus, 
Crangon, Alpheus, Hippolyte, Pandalus, Palemon, Peneus, Mulcion. 
II. STOMAPODA. 
Mysis, Diastylis, Squilla, Gonodactylus. 
Ill. AMPHIPODA. 
Orchestia, Talitrus, Gammarus, Amphithoe, Cerapus, Lepidactylis, Unciola, Hyperia, Podocerus. 
IV, LG2MIPODA. 
Cyamus, Caprella. 
V. ISOPODA. 
Idotea, Stenosoma, Anthura, Spheroma, Nesa, Cymothoa, Limnoria, Asellus, Ligia, Philoscia, 
Oniscus, Porcellio, Armadillo, Fluvicola. 
VI. PGZCILOPODA. 
Polyphemus, Argulus, Caligus, Anthosoma, Pandarus, Cecrops, Lernea, Penella. 
VII. PHYLLOPODA. 
Apus. 
VIII LOPHYROPA. 
Cyclops, Scopiphora. 
IX BRANCHIOPODA. 
Branchipus. 
X. OSTRAPODA. 
Cypris, Cytherina, Daphnia. 
