THE BRAOHYJTRA AND MACRURA OF PORTO RICO. 
125 
carpus less than half the length of merus, distally thickened; palm subcylindrical, slightly compressed, 
not much thicker than carpus; fingers more than half the length of palm. Dactyli of last three pairs 
of feet biunguiculate. Telson short, pointed, on either side with two movable spines, of which the 
inner overreaches the middle point. Length, 44 mm. ; length of second cheliped, 41 mm. 
A marine species, taken at Ponce; Light-House Reef, Arroyo; Ensenada Honda, Culebra. 
Bermudas, shallow water (Bate); Nassau (Rankin); off Habana, Cuba, 78 fathoms, station 2169 
( Albatross ); between Jamaica and Haiti, 23 fathoms, station 2138 ( Albatross ); Curasao ( Albatross ). 
Genus PALiEMON Fabricius. 
Palsemon Fabricius, Suppl. Entom. Syst., 378, 1798. 
Leander Desmarest, Ann. Soc. Entom. France (2), vn, 87, 1849: Stimpson, Proc. Acad. Nat. Sci. Phila., xii, If) (109), 1860. 
Much like Bithynis, but carapace armed with an antennal and a branchiostegal spine; no hepatic 
spine. Legs of second pair not so greatly developed as in Bithynis. Species for the most part marine 
and of small size. 
Key to the Porto Eicon species of the genus Palsernon. 
A. Rostrum with 8 or 9 teeth on upper margin, 3 or 4 on lower margin. Antennal scale very broad, its spine 
not reaching end of blade affinis 
A'. Rostrum with 11 to 13 teeth on upper margin, 5 to 7 on lower margin. Antennal scale very narrow, its 
spine overreaching blade paulensis 
Palsemon aflinis Milne Edwards. 
Palemon affinis Milne Edwards, Hist. Nat. Crust'., n, 391, 1837. 
Palsemon affinis Dana, Crust. U. S. Expl. Exped., I, 584, 1852; pi. xxxvm, f. 5, 1855. Bate, Challenger Rept. Zool., xxiv, 782, 
pi. cxxviii, f. 5, 1888. 
Dorsal crest beginning at middle of carapace, either horizontal or slightly depressed at middle of 
rostrum and ascending toward extremity, reaching to or beyond end of antennal scale; armed with 8 
or 9 teeth, 2 or 3 of which are on the carapace; the last tooth usually near tip of rostrum and separated 
by a considerable distance from penultimate tooth; lower margin of rostrum with 3 or 4 teeth. Adult 
Porto Rican specimens are smaller than those from New Zealand before me, and have 8 to 10 segments 
of upper flagellum of antennula united and 12 to 16 free; whereas the New Zealand specimens have 
12 to 14 united and 20 to 25 free. Carapace of second pair of feet reaching to or beyond the tip of the 
rostrum; slightly longer than the palm. Palm 1.5 times as long as the fingers, not swollen, a little 
wider than distal end of carpus. 
Length of ovigerous female from Fajardo, Porto Rico, 35.5 mm.; length of carapace and rostrum, 
16.1 mm.; length of rostrum, 8.5 mm. 
Porto Rico; Puerto Real; Boqueron Bay; Arroyo; Hucares; Fajardo. 
New Zealand (Milne Edwards, Dana, U. S. Nat. Mus.) ; Port Jackson, Australia (Bate); Bermu- 
das (Heilprin, Ortmann). 
The rostrum of the New Zealand specimens in the National Museum is almost horizontal, but in 
Porto Ric-an specimens it resembles Bate’s figure of an adult female of approximate size. Specimens 
of Palsemon squilla from Jersey in the National Museum have the palm twice as long as the lingers. 
Palaemon paulensis (Ortmann). 
Leander paulensis Ortmann, Revista Mus. Paulista, u, 192, pi. i, f. 14, 1897. 
Dorsal crest beginning just in front of middle of carapace, armed with 11 to 13 teeth, the first, 2 or 
3 of which are on the carapace itself; rostrum ascending for its distal two-thirds; lower margin with 
5 to 7 teeth; as long as or a little longer than antennal scales. The antennular peduncle reaches a 
little more than half the length of antennal scale. The outer flagellum has in the type specimens 8 
segments united and 12 free; in specimens in hand 5 to 7 segments are united and 15 to 17 free. 
Antennal scale very narrow, its inner margin very oblique; antero-external spine extending beyond 
blade. Middle of palm of second pair of feet opposite tip of rostrum. Carpus, palm, and fingers 
subequal in length; the carpus may be a little longer than the palm. The carpus increases in size 
distally; the palm is subcylindrical, slightly compressed and swollen, wider than carpus. 
Length of ovigerous female from Marco, Fla., 28.5 mm. 
