CATALOGUE OF THE CRABS OF THE FAMILY PERICERIDA IN THE 
U.S. NATIONAL MUSEUM. 
BY 
Mary J. RATHBUN, 
Department of Marine Invertebrates. 
(With Plates XX VIII-XL.) 
The classification adopted in the following catalogue is that estab- 
lished by Mr. E. J. Miers, in the J ournal of the Linnean Society of 
London, V«!. x1v, pp. 662 to 667, 1879, and modified by him in the 
Challenger Report, Zodlogy, Vol. XVI, 1886. His descriptions of Li- 
binia and Pericera have been amended to receive new species which 
do not appear to be generically distinct. 
In the key are included all the genera supposed to belong to the 
family. The characters distinguishing those genera which have not 
been seen by the writer are inclosed in parentheses. In the key to 
species only those represented in the National Museum are enumer- 
ated. At the end of the catalogue a list is given of the species of 
Pericerid not in the Museum, for the benefit of future students of the 
group, and also to call attention to the deficiencies of the collection in 
the hope that it may be enriched in this direction through gifts and 
exchange. 
Of the fo: ty-eight species of Periceridie contained in the National 
Museum, one is European, two are Kast Indian, and the remainder 
American. Of the latter, eleven are found on the Pacific coast, from 
the Gulf of California to the Galapagos Islands, and thirty-four on the 
Atlantie coast. Of the Atlantic forms, two only range from Massa- 
chusetts southward. The remainder inhabit the southern Atlantic 
States and the West Indies, in many cases extending to Brazil. Fif- 
teen species are described as new, of which six are from the Gulf of 
California, and, with two exceptions, represented by a single specimen 
each. 
In addition to the specimens in the National Museum, the writer was 
enabled to examine also the Periceride in the Museum of Union Col- 
lege, Schenectady, N. Y., and those contained in a collection made in 
the Bahama Islands by Mr. Frederick Stearns, of Detroit, Mich., in 1888, 
and kindly lent by him for study. The latter collection yielded an 
additional species, which is here described. The writer is indebted 
Proceedings National Museum, Vol. XV—No. 901. aa 
