Decapod Crustacea of Bermuda, Part II. 141 



Family PAL.ffiMONID.flE (/>orj) Leach, 1819. 

 Pakcmonina; Dana, op. cit., 1852, p. 569. 

 Palcemonida Bate, op. cit., 1888, p. 778. 



The carapace is well rounded above, not much compressed ; 

 rostrum is usually long and compressed, generally with denticles. 

 Eyes are usually pryiform and rather large, often with an adjacent 

 ocellus on the outer end of the stalk. Antennules with the basal 

 joint wide and excavated above, externally with a spine and scale ; 

 outer flagellum often branched. 



Antennae with a large foliaceous scale or scaphocerite, its 

 thickened outer margin ending in a tooth-like point or spine. 

 Mandibles deeply cleft ; furnished with a molar and a cutting edge ; 

 palpus sometimes lacking, usually with two or three joints. 



Outer maxillipeds are slender, very hairy, leg-like. First and 

 second legs are long, chelate ; chelae of the second pair usually the 

 larger; its carpus is not subdivided. Second pair of legs often 

 very long and strong. Telson is usually narrow, with the margins 

 turned down ; tapering to a narrow tip, armed with two or three 

 pairs of spines. 



Key to the Bermuda genera of Palcer.ionidcc. 



A. Carapace lacks a hepatic spine, mandibles have a palpus. Dactyls 

 simple Leander. 



A'. Carapace has a hepatic spine. 

 B. Mandible has a palpus. 



a. Rostrum strong, with a lateral rib. Legs of second pair are notably 

 long and large : Palamon. 



a'. Rostrum slender and thin, toothed above and below. Second legs 

 not unusually large Palamonella. 



B'. Mandible is without a palpus. 



b. Abdomen unusually elongated and compressed. Dactyl of ambula- 

 tory legs bifid Urocaris* 



b'. Abdomen of the usual form, not notably elongated. Dactyl of 

 ambulatory legs simple Periclimenes. 



* Urocaris longicauda, the type, is not yet positively known to occur at 

 Bermuda. Its range is from Brazil to Beaufort, N. C. Common in the 

 West Indies and Florida Keys. The type-species has the dactyls of the 

 ambulatory legs biunguiculate ; others referred to the genus have them 

 simple. 



