102 BULLETIN 51, UNITED STATES NATIONAL MUSEUM. 



P. 1068. The classification and geographical distribution of the pearly 

 fresh-water mussels. By Charles T. Simpson. 



pp. 295-343. 1 plate. 



P. 1069. Note on the occurrence of an armadillo of the genus Xenums 

 in Honduras. By Frederick W. True. 



pp. 345-347, 2 pis. 



P. 1070. The genus Callinectes. By Mary J. Rathhun.. 



pp. 349-375, 17 pis. 



P. 1071. Descriptions of two new species of fresh- water crabs from 

 Costa Rica. By Mary J. Rathbun. 



pp. 377-379, 2 pis., 3 figs. 



P. 1072. Description of four new triassic unios from the,s^ked plains 

 of Texas. By Charles T. Simpson. 



pp. 381-385, 5 figs. 



P. 1073. Revision of the North American Empidse a family of two- 

 winged insects. By D. W. Coquillett. 



pp. 387-440. 



B. 1074. Description of a new subspecies of the genus Peucedramus 

 Coues. By Robert Ridgway. 



p. 441. 



P. 1075. Preliminary diagnoses of new mammals from the Mexican 

 boundary of the United States. By Edgar A. Mearns. 



pp. 443-447. 



P. 1076. Characters of a new American family of passerine birds. By 

 Robert Ridgway. 



pp. 449-450. 



P. 1077. Osteological and pterylographical characters of the Procnia- 

 tida3. By Frederic A. Lucas. 



p. 505-507, 5 figs. 



P. 1078. Catalogue of a collection of birds made by Dr. W. L. Abbott 

 in Kashmir, Baltistan and Ladak, with notes on some of the 

 species, and a description of a ne v species of Cyanecula. 

 By Charles W. Richmond. 



pp. 451-503. 



P. 1079. On birds collected by Dr, W. L. Abbott in the Seychelles, 

 Amirantes, Gloriosa, Assumption, Aldabra, and adjacent 

 islands, with notes on habits, etc., by the collector. By 

 Robert Ridgway. 



pp. 509-646. 



P. 1080. Descriptions of two new subspecies of the downy woodpecker, 

 Dryobates pubescens Linneeus. By Harry C. Oberholser. 



pp. 547-550. 



P. 1081. Preliminary description of a new subgenus and six new spe- 

 cies and subspecies of hares, from the Mexican border of the 

 United States. By Edgar A. Mearns. 



pp. 561-565. 



