vl INTRODUCTION. 
of the Ceuthorrhynchini, owing to the absence of their food-plants (certain Crucifere, 
Boraginace, Labiate, Composite, &c.). 
The Barina are extraordinarily numerous in genera and species throughout the 
greater part of the American continent. Of the eleven groups, however, under which 
the Central-American forms are here placed, eight do not extend north of Mexico, the 
other three, the Centrinides, Madarides, and Barides, being well represented in the 
United States, some genera—Baris s. str. and Onychobaris—becoming more numerous 
in species northward, and others—Gerwus and Pseudobaris—increasing southward. 
These insects, so far as at present known, attack the stems, nuts, or fruits of various low 
plants, shrubs, and trees. Species of the under-mentioned genera have been observed in 
connection with plants of the following Natural Orders :—Ceuthorrhynchidius (Papave- 
racer), Ambates, Trichobaris, and Lepidobaris (Solanacee), Peridinetus (Piperacese and 
Melastomacee), Optatus (Anonacee), Gerwus (Composite, Euphorbiacee, and Poly- 
gonacee), Baris and Catapastinus (Composite), Pseudobaris (Labiate), Zygobaris and 
Amercedes (Rutacee), Onychobaris (Cactacee), Busckiella (Myrtacez), Orthoris (Loasez), 
Nicentrus (Euphorbiacee and Polygonacee), &c. ; but it is probable that in some cases 
the insects have simply been attracted by the flowers, especially in the case of those 
found upon the Anonacee and Euphorbiacee. The metallic European species of Baris 
are mostly attached to Cruciferee or Resedacee, and the type of Limnobaris (L.T-album, 
J..)—a genus with numerous representatives in Central America—to Cladium mariscus 
(order Cyperacez), a plant also inhabiting the warmer parts of the New World. In 
dealing with the three northern sections of the Barina I have found Colonel Casey’s 
paper [Ann. N. York Acad. Sci. vi. pp. 461-684 (1892)] of great assistance, so many of 
the genera being common to Mexico and the United States. Some of the commoner 
and more widely distributed members of this group (e. g. Baris @rea and Pseudobaris 
undulata and acutipennis) are so variable that till they are bred it will probably be 
found impossible to define them satisfactorily. 
We are again indebted to Dr. Yngve Sjéstedt for the loan of the Mexican types of 
the species characterized in Schénherr’s work ; to Dr. K. M. Heller for communicating 
many types of Kirsch and Faust; and to Signor A. Solari, of Genoa, for lending us 
the Barids recently described by him, and also for placing his unworked material at 
our disposal, allowing us at the same time to retain for the British Museum the types 
of the additional species recorded in this Volume. Thanks to the kindness of the 
Director of the Smithsonian Institution, the Mexican and Central-American Barids 
