DECAPOD CRUSTACEANS OP THE BEAUFORT, N. C, REGION. 393 



Abdomen bent and slightly humped at end of third segment. Upper surface of telson slightly 

 grooved and with four small spines. 



length of a female, 45 mm.; carapace, including rostrum, 16 mm.; rostrum, 9 mm. 



This shrimp has been collected from floating Sargassxtm in the harbor, from the piles of the town 

 wharves, and outside the harbor, by the Fish Hawk. 



Genus PALiEMONETES Heller. 



Pal^BtntmeUs Heller, 1869, p. 157. 



KEY TO THE SPECIES OF THE BEAUFORT REGION. 



a. Second pair of legs long, considerably exceeding the rostrum. 



b. Fifth pair of legs not reaching the tip of the rostrum ; marine carolinus. 



bb. Fifth pair of legs exceeding the tip of the rostrum; fresh water exilipes. 



aa. Second pair of legs shorter, hardly reaching the tip of the rostrum; marine vulgaris. 



Palaemonetes carolinus Stimpson. PI. xxvii, fig. 4. 



PaltEmoneUi carolinus Stimpson, 1874. p. 129; Kingsley, 1878-79. p. 330; Fowler, 1912, p. 32S. 



Integument moderately firm. Carapace rounded above, anterior margin with suborbital and 

 branchiostegal spines; rostrum slightly exceeding the antennal scales, thin, deep, upcurved in distal 

 half at least, armed above with 8 or g teeth and below with 4 or 5, the intervals between the teeth ciliated 

 and the posterior one of the upper surface somewhat removed from the others and belonging, perhaps, 

 to the carapace. 



Antennular peduncle shorter than antennal scale; inner flagellum slender; outer flagellum with 

 the basal articles thickened and bearing at about the eighth article an accessory branch of about twelve 

 articles. Antennal flagellum considerably longer than body; scale foliaceous, its sides tapering slightly 

 to an obliquely rounded tip which usually fails to reach the end of the rostrum. First pair of legs short, 

 reaching scarcely beyond the carpus of the second pair. Second pair of legs very long, exceeding the 

 rostrum by almost the length of the hand; fingers a little shorter than the palm. Distal end of fifth 

 legs not extending to the tip of the rostrum. 



Abdomen rather stout, bent but not conspicuously humped at the fotuth segment. Telson taper- 

 ing, its sides straight, tip with two long slender spines, upper surface with four small spines. 



Length of a female, 24 mm. ; carapace, including rostrum, 10 mm. ; rostrum, 6 mm. 



Color in life, almost transparent; in alcohol, milky white. 



It occurs in abundance in the eel grass and about the margins of the marsh in all parts of the harbor, 

 usually in company with P. vulgaris. 



Palaemonetes vulgaris (Say). PI. xxvii, fig. 5. 



PalfEmon vulgaris Say, 1818. p. 248; Coues, 1871, p. 124. 



PaUBTnoneUs viUgaris Stimpson, 1871, p. 129; Smith, 1873, p. 550; Kingsley, 1878-79, p. 330; Paulmier, 1905, p. 132; 

 Sumner, 1911, p. 663; Fowler, 1912, p. 324, pi. 94. 



Similar to P. carolinus except as follows: The dorsal spine of the carapace is lacking or is moved 

 forward tmtil it forms a part of the series of rostral teeth. The tip of the rostrum is more acute, the teeth 

 of the upper margin are smaller and more acute, and those of the lower margin number two or three. 

 The antennular peduncle is as long as the antennal scale. The second pair of legs is much shorter, 

 hardly reaching the tip of the rostrum, and the fingers are considerably shorter than the palm. 



Length of a female, 31 mm.; carapace, including rostrum, 12.5 mm.; rostrum, 6 mm. 



This species, often found in company with P. carolinus, has also been taken frequently in floating 

 Sargassum. In August, 1915, it was found in great numbers in a small pool of slightly brackish water 

 close to Newport River about 3 miles north of the laboratory. 



Palsemonetes exilipes Stimpson. PI. xxvii, fig. 3. 



?Hippolyte paludosa Gibbes, 1850, p. 197. 



Palasmonetes paludosa Kingsley, 1878a, p. 97. 



Paltzmonetes exilipes Stimpson, 1871, p. 130; Smith, 1874, p. 641, pi. I, fig. i. 



Integument thin and transparent. Carapace subcylindrical, smooth, with slender and acute 

 suborbital and branchiostegal spines; rostrum long, slender, compressed, gently ctu-ved upward dis- 



