MAIOIDEA. o-j 



G. 6. Hyastenus, White*— Chorino affinis. Rostrum pralonguin, cornubus non 

 depressis,^ ante poneque oculos directus. Margo orbitalis superior unifissus, 

 Pedes 2di longiores. 



9. PYRIN^E.— Carapax subpyriformis. Pedes 8 postici valde com- 

 pressi. 



G. 1. Pyria, Dana. — Carapax depressus, inermis, rostro lamellato, cornubus 

 ovatis. Oculi perbreves, orbits spinis non arniata. 



b. OCULI LONGITUDINALITER PORBECTI, CARAPACE ANTICE TRUNCATO. 



10. OTHONINiE.— Carapax antice late truncatus, rostro fere obso- 

 lete. Oculi elongati, cylindrici. 



Gr. Othonia, 2fe£f— Carapax parce oblongus, suborbicularis, rostro bifido. An- 

 tennae intern® minutissimae; externae latae, articulo lmo lato, 2do valde depresso, 

 inverso-subtriangulato. 



B. Carapax paulo transversus. 



11. SALACINiE.— Carapax fere orbicularis. Pedes 8 postici crassi, 

 longi, articulo penultimo infra recto. Rostrum fere obsoletum, in- 

 tegrum. 



G-. Salacia, Edwards et Lucas. J— Carapax gibbosus. Fossa antennalis sub rostro 

 partim excavata. Articulus maxillipedis externi 3tius medio apice emarginatus, 

 hacque emarginatione articulum proximum gerens. Itiacho Grapsoque affinis. 



2. DIGITI APICE OBTUSI, INSTAR COCHLEARIS EXCAVATI. 



12. MITHRACINyE. — Oculi mediocres. Carapax sive paulo ob- 

 longus, sive transversus. 



(x. 1. Mithrax, Leach.§ — Carapax saepe orbiculato-ovatus, interdum transversus. 

 Eostrum aut saliens aut fere obsoletum, bifidum. Articulus antennarum exter- 

 narum lmus apice externo cjjiabus spinis longis armatus. 



* Ann. Mag. Nat. Hist. [2], xx. 61, and Crust. Toy. of Samarang, p. 11. The spe- 

 cies in Seba's fig. 12, pi. 18 of the Thesaurus. 



f Zool. Trans., ii. 55. 



X Crust, in D'Orbigny's S. Amer., 12, pi. 11. 



§ The characters given by White for his genus Schizopkrys (Ann. Mag. % H. [2], ii. 

 282, 283, and Voy. Samarang, Crust., p. 16), do not serve to exclude the species from 

 Paramithrax, Maia or Mithrax. The peculiarity of the orbit described and of the first 

 joint of the outer antenme, as far as understood by the writer from the description, are 

 the same as in the genera just mentioned. 



The genus Dione of De Haan (Fauna Japon. Crust., p. 82) differs from Mithrax only 

 in not having the interior apex of the third joint of the outer maxillipeds project inward 

 a little over the insertion of the fourth joint. It corresponds to "Mithrax triangv- 

 laires" of Edwards. 



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