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NORTH AMERICAN FAUNA. 



some annoyance by walking over us at night while we were camped in their haunts. 

 They began to come out of their burrows as soon as it became twilight in the even- 

 ing. In both localities most of their burrows were found among the scrubby bushes. 

 On Isabel Island they were often seen during the day sitting in the burrows a foot 

 or so from the entrance, but scuttled back to a safe depth when I approached. 



Ocypode • occidentalis Stimpson. 



Ocypoda occidentalis Stimpson, Ann. Lyc. Nat. Hist. N. Y., VII, 229, 1860. 

 Maria Magdalena Island. May 28. One female (No. 689). 

 Maria Cleofa Island. May 30. One male (No. 699). 



This much neglected species is distinct, it seems to me, from 0. Icuhlii 

 de Haan, of which Miers made it a variety. According to the descrip- 

 tion of 0. Jcuhlii given by de Man (Notes Leyden Mus., Ill, 250, 1881), 

 who had the type before him, 0. occidentalis differs from it in having a 

 narrower carapace, in the outer orbital angle directed inward and not 

 outward, in the shorter hand, the length of the upper margin of the 

 palm being less thau the width, and in having from 18 to 21 tubercles 

 in the stridulating ridge (de Man gives 8 or 10 for Mihlii, while Miers 

 figures 17). The form of the abdomen of the male furnishes excellent 

 characters for the determination of the species of Ocypode. In 0. occi- 

 dentalis the penultimate segment is much wider at its middle than at 

 its proximal end. 



It is singular that this species is not mentioned in the revisions of 

 the genus by Kingsley, 1880, or by Ortmaun, 1897. 



Dimensions of a type specimen^ U. 8. National Museum. — Male: Length, 

 40.5 mm.; epibranchial width, 48 ; exorbital width, 41; length of supe- 

 rior margin of palm, 22.8; entire length of propodus, 43.5; greatest 

 width, 24. 



Range. — Type locality, Cape St. Lucas. Also taken at Turtle Bay 

 and San Jose del Oabo, Lower California, by Mr. A. W. Anthony, in 

 1896 and 1897. 



Grapsus grapsus (Linnteus). 



"This crab was very abundant on the rocks along the water's edge 

 on the Tres Marias as well as on Isabel Island." (Nelson.) 



The species is distributed throughout the tropics. 



Bithynis jamaicensis (Herbst). 

 Maria Magdalena Island. May 27. One adult, 7 young (No. 709). 

 Maria Cleofa Island. May 30. One adult, 3 young (No. 710). 



"These shrimps were very numerous in a small stream among the 

 hills in the interior of Maria Magdalena, and were also numerous in 

 streams flowing through the hilly parts of the adjacent mainland." 

 (Nelson.) 



The species is found on the Pacific slope of the continent from Lower 

 California to Ecuador, and on the Atlantic slope from Texas to Rio 

 de Janeiro. The following localities, not before recorded, are repre- 

 sented by specimens in the U. S. National Museum: On the Pacific 



Wcij2)ode, not Ocypoda, Tabricius, Entom. 8y8., Suppl., 312 and 347, 1798; also 

 Entom. Sys., emend, et auct., IV, index, 115, 1796. 



