KEY TO GENERA AND SPECIES IN THE CAROLINAS 



(Holthuis, 1952, modified) 

 a. Hepatic spine present, branchiostegal spine absent ; 

 chelate second legs enlarged and greatly elongated, 

 b. Dactyls of last three legs bifurcate ; marine 



Braehycarpus biitngiiiciilatus (p. 51). 

 bb. Dactyls of last three legs simple ; fresh or brackish 



water Macrobrachium (p. 52). 



c. Fingers of chelae on second legs thickly pubescent 

 throughout length ; rostrum with teeth extending 



up to tip M. acanthurus (p. 52). 



cc. Fingers of chelae on second legs with scattered 

 hairs, except thicker on ringers along cutting edges ; 

 rostrum with toothless daggerlike tip 



M. ohione (p. 54). 

 aa. Hepatic spine absent, branchiostegal spine present; 

 chelate second legs not greatly enlarged. 



b. Mandible with a palp Leander tcnuieornis (p. 55). 



bb. Mandible without a palp Palaemonctcs (p. 56). 



c. Carpus of second leg in adult female shorter than 

 palm, in males slightly longer or shorter (1.1 

 times) than palm; dactyl of second leg with two, 

 immovable finger with one tooth on cutting edge ; 

 rostrum with first two teeth of dorsal margin 

 behind orbit, dorsal rostral teeth reaching to apex, 



lower margin with three to five teeth 



P. vulgaris (p. 56). 



cc. Carpus of second leg in adult female much longer 



than palm (1.3 to 1.5 times), in males almost as 



long as whole chela ; dactyl of second leg with a 



single tooth or without teeth, immovable finger 



without teeth on cutting edge ; rostrum with only 



one dorsal tooth behind orbit. 



d. Dorsal teeth of rostrum reaching up to apex, 



apex often bifurcate ; lower margin of rostrum 



with four or five, seldom three teeth ; dactyl of 



second leg with one distinct tooth on cutting 



edge P. intermedins (p. 58). 



dd. Dorsal and ventral margins of rostrum with an 

 unarmed stretch before dagger-shaped tip ; lower 

 margin of rostrum with two to four, generally 

 three, teeth ; fingers of second leg without teeth 

 on cutting edges P. pugio (p. 59). 



Genus Braehycarpus Bate, 1888 



Holthuis, 1952, p. 2.— Hemming, 1958b, p. 154. 



Figure 42. — Braehycarpus biunguiculatus (Lucas). A, 

 carapace in lateral view, X 6 ; B, antennule, X 7 ; C, 

 antenna, X 7 ; D, first leg, X 6 ; E, left second leg, X 6 ; 

 F, right second leg, X 6 ; G, third leg, X 6 ; H, dactyl 

 of third leg, X 16; I, telson, X 15 (after Schmitt, 1939). 



Braehycarpus biungiuculatus (Lucas) 



Figure 42 



Palaemon biunguiculatus Lucas. 1849, p. 45, pi. 4, fig. 4. 

 Braehycarpus biunguiculatus: Holthuis, 1952, p. 3, pi. 1, figs. 

 a-q (rev.). 



Recognition characters. — Rostrum well de- 

 veloped, rather high, directed straight forward, 

 reaching about to end of antennal scale; upper 

 margin with seven (seldom eight) teeth, first two 

 teeth placed behind orbit with first tooth at about 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



midlength of carapace; lower margin with three 

 (seldom two or four) teeth. Carapace smooth; 

 antennal and hepatic spines present; a strong 

 postorbital ridge paralleling orbit. Eyes well de- 

 veloped. Basal article of antennular peduncle 

 with anterolateral spine strong, reaching beyond 

 second article of peduncle ; stylocerite small, acute, 

 closely appressed to article; rami of inner anten- 

 nular flagellum fused for 8 to 23 joints; free part 



51 



