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Zoology. 127 



4, POLIDECTIN-^. — Antennae internee transversa?. Antennce ex 



tern^e basi solutse, liberae. — An Pilwnnis propinquiori 



? 



G. PoLYDECTUS, Edw,^ — Orb'ita dentibus tribus infra instructa. 

 Manus elongala, digitis preelongis, aitenualis, uncinatis, cum den- 

 tibus tenuiter spinuliformibus saepe armatis. 



•Fam. II. ERIPfllD^. 



Pedibus maxillipedeque Imo Cancridis affinis. Palatum colliculo 

 ( usque ad marginem anticum produclo utrinque divisum- Carapax 



sjepius angustus, interdum latus, latiludine ante-mediana srepissime ma- 

 jore, oculis remotis, 



-■ 



!• CETHRlNiE. — Carapax transversus, lateribus valde dilatatus et 

 rotundatus. Anlennoe internae fere longlludinales. 

 G. L QEthra, Leach. 



2. OZIN^, — Carapax plus minusve transversus. Digiti acuminati. 

 Anlennse internee IrunsversHe. Orbita hiatu interno basi antennae oc- 

 cupalo instrucla. Abdomen maris 7-articulatum. 



1. Articiilus antennce externcB \mus frontem lene altingens. 



G. 1. Galene, De Haan.f — Carapax transversus, longiiudinaliter 



multo convexus, anlice decllvis. — An Potami^e propinquior? 

 G. 2. Ozius, Leach. — Carapax transversus, latus, fere planus. 



2. Articulas antenncB extern(z Imus frontem non atlingens. 



G. 3, PsEUDozius, Dana.X — Carapax transversus, fere planus, 

 latior, margine antero-Iaterali breviore. 



G. 4. PiLui\iNUs, LeacK — Carapax angustus, parce transversus, 

 s^pius convexus, marline anlero-iaterali breviore. 



G. 5. PiLUMNOiDEs, Edw, et Lucas.^ — Carapax angustus, parce 

 transversus, valde convexus, marline antero-lalerali longiore, 

 bene arcuate, super carapacem postice incurvato. 



This genus is very peculinr in the hand : both fingers are long stylifonn and 

 very slender, with incurved apices, and hardly touching except at tips, and when den- 

 tate the teeth are delicate spines on the inner margin ; moreover, the part of the liand 

 anterior to the lingers is quite short, A species collected by the writer is closely 

 hke the P. cupuUfer in most of its characters. The form of the hand is very unlike 

 anything among other Cancroidea ; and Halimede which has been supposed to be 

 '^^^J, I'^ydectus, has (Uke MedcTus) the ordinary form, hke that in Xantho. 



Ihe genus Ipkiculus of Wliite (Crust, Voy. Samarang, 57, pi. 13, f. 5), lias the gene- 

 ral characters of our Polydectus — the same villous coat, similar fingers, even to the 

 epmiform dentation of the fingers, and other resemblances ; and we suspect although 

 a broader species, that his L spongiosum is a true Polydectus. 



. J he specimen of the Polydectus, from which a description with a colored draw- 

 ?^g Was taken by me while it was living, is not now found in our collections, and 

 tJi ^^* therefore been able to ascertain the character of the prselabial plate and 

 ^«us assure myself wliether the species are related to the Eriphidffi or not. It is very 

 possible that the true pkce is after Offl'me, 



t ^^aun.Japon. 19. 



+ ^ear Pseudocarcinus, from which it differs in the ridge on the pralabial plate, 

 as well as in its flatter form. 



fe Crust D^Orb. S. Am, 21. 



