NO. 2047. AMERICAN BRACnYiRHYNCHOUS CRABS— RATHBUN. 127 



third, and the whole of the distal half is much wider than in the new 

 species. The spiniform finger tips are not strongly bent in monilifera. 



The ambulatory legs are almost bare except the dactyli. 



The chief difference m the form of the male abdomen of the two 

 species lies hi the penultimate segment: m monilifera it is less than 

 twice as wide as it is long; in maracoani just twice as wide as long. 



UCA MUSICA, new species. 

 Plate 10. 



Gelasimus gibbosus Streets (not Smith), Bull. U. S. Nat. Mus., vol. 7, 1877, 



p. 113. 

 Uca stenodactyla Ortmann, Zool. Jalirb., Syst., vol. 10, 1897, p. 356 (part). 

 TJca stenodactylus Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898, p. G03 (not 



synonymy). 



Type-locality. — Pichihnque Bay, Gulf of Cahfornia, U. S. Fish- 

 eries steamer ^ZSa^ross, 1888; 1 male. 



Type.— Cat. No. 22081, U.S.N.M. 



Distrihution. — From San Diego, California, to Mazatlan, Mexico; 

 occasionally farther north. San Diego (Ortmann) j San Bartolome 



a 



Fig. 5.— Uca musica. a. Lower view of large (left) chela of male 



TYPE, SHOWING STRIDULATING RIDGE, X 3^. b. ANTERIOR (LOWER) VIEW 

 OF PORTION OF FIRST LEFT AMBULATORY LEG OF MALE TYPE, SHOWING 

 GRANULES WHICH PLAY AGAINST STRIDULATING RIDGE, X 3J. 



Bay, Lower California (Lockington) ; La Paz (Streets), specimens in 

 United States National Museum; Guaymas Bay, Wilham Palmer, 

 collector; Mazatlan, C. H. Gilbert, collector; Seattle, Washington, 

 D'Arcy W. Thompson, collector, photographs of large chela in United 

 States National Museum; Vancouver Island, B. C, pliotogi-aphs 

 received from C. F. Newcombe. 



Dimensions. — Type male; length of carapace 8 mm.; width 12.9 

 mm. 



Very like Uca stenodactylus (Milne Edwards and Lucas), ^ which 

 ranges from Salvador, Central America, to Valparaiso. Differs as 



^Gelasimus stenodactylus Milne Edwards and Lucas, Voy. dans I'Am^r. M^rid. par d'Orbigny, vol. 6, 

 1844, Crust., p. 26; vol. 9 (atlas), 1847, pi. 11, fig. 2. 



