LEUCOSOIDEA. 39 1 



G. 1. Calappa, Fabr. — Carapax valde transversus, lateribus alate expansis, pedes 

 plerurnque tegentibus. 



G. 2. Platymera, Edw. — Carapax transversim ellipticus, lateribus non expansis. 

 Maxillipedis externi articulus 3tius 4tuni margine interno gerens. 



G. 3. Mursia, Edw. — Carapax fere orbiculatus, parce transversus, lateribus non 

 expansis. Maxillipedis externi articulus 3tius 4tum margine apicali gerens, 2do 

 non longior. Tarsi quinti styliformes. 



G. 4. Cycloes, De Haan* — Carapax suborbiculatus, ssepius non transversus, late- 

 ribus non expansis. Maxillipedis externi articulus 3tius 2do longior. Tarsi 

 quinti anguste lanceolati. 



Subfam. 2. ORITHYIN^E.— Pedes 8 postici natatorii. 



G-. Orithyia. — Carapax suborbiculatus, non transversus, antice truncatus. 



Fam.II. MATUTIDiE. 



Gr. 1. Hepatcts, Latr. — Carapax valde transversus. Pedes nulli natatorii. 

 Gr. 2. Thealia, Lucas.'f — Carapace Matutce affinis. Pedes nulli natatorii. 

 Gr. 3. Matuta, Fabr. — Carapax suborbiculatus. Pedes 8 postici natatorii. 



Fam. III. LEUCOSIDiE. 



A. CARAPAX LATERE SSEPIUS NON DILATATUS, LATERIBUS PEDES RETRACTOS 



NON TEGENTIBUS. 



1. Carapax lateribus non spinigerus nee cylindrice productus. Articulus maxillipedis 



externi dtius subtriangulatus. 



1. Palpus maxillipedis externi latissimus, maxillipede multo latior. [Carapax inermis. 

 Area buccalis subquadratus.] 



G. 1. Philyra. — Carapax suborbiculatus, inermis, non tuberculatus, fronte poste- 

 riore quam epistoma. Antennae internee transversa. 



2. Palpus maxillipedis externi maxillipede aut vix latior aut angustior. 



a. Pedes antici breves vel mediocres, crassi. [Carapax inermis. Area buccalis subtrianffulata.] 



G. 2. Leucosia, Fabr. — Carapax non tuberculatus, latere non dilatatus, antice 

 anguste productus, extremitateque oculos minutos autennasque gerens. Palpus 

 maxillipedis externi longus et latus, extus non dilatatus. Pedes antici medio- 

 cres. 



* De Haan, Faun. Japon., 67, 69, Decas Tertia, 1837, and p. 125, Decas Quinta. 

 Cryptosoma of Brule, Edwards's Crust., ii. 110, 1837, and lies Canar. Ent, p. 16. 

 f Lucas, Ann. de la Soc. Ent. de France, viii. 573, tab. 21. 



