Recognition characters. — Rostrum reaching to 

 or slightly beyond end of antennal scale; tip di- 

 rected upward making upper margin more or less 

 concave; upper margin with 8 to 11 teeth, first 

 2 teeth behind orbital margin and separated more 

 widely than other proximal teeth, all teeth rather 

 regularly distributed along rostrum but proximals 

 generally closer together than distals, no unarmed 

 space behind tip, tip often bifurcate; lower mar- 

 gin with 3 to 5 (usually -1) teeth. Carapace 

 smooth; antennal spine present; branchiostegal 

 spine on anterior margin just below branchiostegal 

 groove. Eyes well developed. Basal article of 

 antennular peduncle with slender stylocerite 

 reaching slightly beyond middle of article, 

 anterolateral spine of article strong, overreaching 

 rounded anterior margin; upper antennular 

 flagellum with both rami fused for 7 to 9 joints; 

 free part of shorter ramus with 10 to 17 joints, at 

 least 1.5 times as long as fused portion. Antennal 

 scale 3 times longer than broad; terminal tooth 

 strong, reaching almost to end of lamella. 



Figure 47. — Palaemonetes (Palaemonetes) vulgaris 

 (Say). A. anterior part of body in lateral yiew : B. 

 antennnle ; C, antennal scale : D, second leg of female : 

 E, fingers of second leg of female : F. second leg of 

 male; G, third leg: A-G X 5 (after Holthuis, 1952). 



First leg usually not reaching to end of anten- 

 nal scale; fingers about as long as palm; carpus 

 1.3 to 1.7 times as long as chela and a little longer 

 than merits. Second legs longer and stronger 

 than first, stronger in adult females than in males 

 with fingers and sometimes entire palm reaching 

 beyond scale; fingers a little over half length of 

 palm, cutting edge of dactyl with two small teeth 

 proximally, immovable finger with one similar 

 tooth fitting between those of dactyl; carpus 

 shorter than palm and about three-fourths length 

 of merus. Second legs of male not so large as in 

 female; teeth on fingers indistinct. Third leg 

 with propodus less than twice length of carpus. 

 Fifth leg with propodus about three times length 

 of dactyl, twice as long as carpus. 



Abdomen smooth; fifth segment with tip of 

 pleura rectangular or slightly acute. Sixth seg- 

 ment 1.5 times length of fifth, shorter than telson. 

 Telson with two pairs of dorsal spines; anterior 

 pair somewhat behind middle; second pair half- 

 way between these and tip ; posterior margin with 

 strong median point flanked by two pairs of 

 spines, inner pair longest and between them two 

 feathered setae. Outer margin of uropodal exopod 

 with a strong terminal tooth flanked by a slender 

 movable spine medially. 



Measurements. — Length of body : male, 30 mm. ; 

 ovigerous females, 22 to 42 mm. 



Color. — Transparent in life. 



Habitat. — Estuarine waters, especially in beds 

 of submerged vegetation; water's edge to (rarely) 

 S fathoms. Salinity of 3°/ 00 is apparently lethal 

 (Nagabhushanam, 1961). 



Type locality. — Atlantic coast of United States. 



Known range. — Barnstable County, Mass., to 

 Cameron County, Tex. (from specimens exam- 

 ined by Holthuis, 1952). Literature records: 

 Gaspe, Quebec, Canada, to Rio Champoton and 

 near Progreso. Yucatan, Mexico (Holthuis, 1952). 



Remarks. — Correct identification of the species 

 of Palaemonetes occurring on the east coast of 

 the United States was not possible until Holthuis 

 (1949) introduced his key. As Holthuis (1952) 

 pointed out, two names, vulgaris and carolinus, 

 were applied indiscriminately to three species but 

 the description of carolinus was actually based on 

 a specimen of vulgans ; hence, this name is a syno- 

 nym of vulgaris. With the status of vulgaris 

 stabilized, Holthuis went on to show that two 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



57 



