Portunidae
- Portunus
Type genus of the family Portunidae.
- Ovalipes
A genus of Portunidae.
- Callinectes
New World blue crabs.
Amphipoda
Limulidae
- Limulus
Type genus of the family Limulidae.
- Tachypleus
A genus of Limulidae.
Branchiopoda
- genus Daphnia
Water fleas.
- Triops
Type genus of the family Triopidae: small crustaceans with a small third median eye.
Brachyura
Argiopidae
- Aranea
A genus of orb-weaving spiders including common garden spiders and barn spiders.
- Argiope
The type genus of Argiopidae; small genus of orb-weaving spiders.
Majidae
- Maja
Type genus of the Majidae; nearly cosmopolitan in distribution.
- Macrocheira
Giant crabs of Japan.
Ixodidae
- Ixodes
Type genus of the family Ixodidae.
- Dermacentor
Vectors of important diseases of man and animals.
Astacidae
Mysidae
Also contains
- Cancer
Type genus of the family Cancridae.
- Homarus
Type genus of the family Homaridae: common edible lobsters.
- Artemia
Fairy shrimp; brine shrimp.
- Pinnotheres
Type genus of the family Pinnotheridae: pea crabs.
- Palaemon
Type genus of the family Palaemonidae; widely distributed genus.
- Porcellio
Old World genus of isopod crustaceans.
- Orchestia
Type genus of the family Orchestiidae.
- genus Architeuthis
Giant squid.
- genus Cyclops
Copepod water fleas.
- Phalangium
Type genus of the family Phalangiidae.
- Chelifer
A genus of Chelonethida.
- Mastigoproctus
Giant whip scorpions.
- Paralithodes
A genus of Lithodidae.
- Latrodectus
Venomous spiders.
- Lycosa
Type genus of the family Lycosidae.
- Palinurus
Type genus of the family Palinuridae.
- Pagurus
Type genus of the family Paguridae.
- Trombicula
Type genus of the family Trombiculidae.
- Sarcoptes
Type genus of the family Sarcoptidae: itch mites.
- Peneus
Type genus of the family Peneidae.
- Panonychus
A genus of Tetranychidae.
- Scutigerella
Garden centipedes.
- genus Squilla
Type genus of the family Squillidae.
- Armadillidium
Type genus of the Armadillidiidae.
- Scutigera
A genus of Scutigeridae.
- Oniscus
Type genus of the Oniscidae; woodlice that cannot roll into a ball.
- Geophilus
Type genus of the Geophilidae: a cosmopolitan genus of centipedes sometimes called ea...
- Nephrops
A genus of Nephropsidae.
- Crangon
Type genus of the family Crangonidae.