344 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



studies contained several new genera and species but nothing of a 

 synoptic nature. In 1875 Uliler began a series of contributions that 

 proposed new genera and species in that year and the next, and 

 eventually, in 1877, led to a monograph on the Cydnidae known to 

 occur in North America. Uhler's works, which first introduced the 

 use of the important osteolar structures, appear to have been inclusive 

 and careful studies and they do not exhibit excessive generic splitting 

 as certain later authors seem to have believed. Shortly after Uhler's 

 monograph, Carlos Berg (1879, 1884, 1891) published some im- 

 portant studies on Argentine and Brazilian forms. Unfortunately, 

 even though Berg was corresponding with StS,l, his identifications 

 were not rehably accurate and his descriptions were not diagnostic. 

 In 1880 the first volume on the Rhynchota in the now-famous Biologia 

 Centrali-Americana appeared. The list of cydnids known from the 

 included territory, including descriptions of new forms, was by 

 Distant. No keys were given in the cydnid section and the colored 

 illustrations offer little help in identifying the species. 



Returning again to publications with a world-wide scope, one 

 finds a list of known species in StkVs (1876) "Enumeratio." In 1879 

 Signoret began a series of cydnid studies that eventually culminated 

 in a "Revision" that appeared in a series of papers from 1881 to 1884. 

 This revision, the only attempt to include all the forms of the world 

 in a single such study, contained a key to genera, descriptions of genera 

 and species, and 228 attractively executed illustrations. Unfortun- 

 ately, the line appearance of the paper is misleading when an attempt 

 is made to use it. There are several serious errors in the key, the 

 descriptions and illustrations are often inaccurate, and certain earlier 

 species are omitted. In addition, the generic conclusions presented 

 there are not supported by the present study, particularly those which 

 led Signoret to synonjnnize many of Uhler's genera and to create a 

 number of monobasic genera. The "Catalogue General des Hemip- 

 teres" by Lethierry and Severin (1893) was the last major catalog* of 

 the species for the world. 



Smce the turn of the centurj'^ several papers have presented keys 

 to permit identification of cydnids from one or more countries within 

 the scope of the present paper. They were Barber and Bruner's 

 (1932) Cuban study. Barber's (1939) report on most of the Hemiptera 

 of Puerto Rico and the Virgin Islands, and Torre Bueno's (1939) 



< KirkaMy's second part of his general catalog of the Hemiptera had been completed in manuscript and 

 was partiaUy in galley proof at the time of his death. Unfortunately, this second part of the catalog was 

 never brought to publication. Instead, the manuscript and partial galley proof were eventually deposited 

 in the U.S. National Museum. Through the very generous cooperation of Dr. Reece Sailer of that institu- 

 tion, the manuscript and galley proof were entrusted to me during these studies. They have been of inesti- 

 mable value. Some consideration was given to the possibility of bringing Kirkaldy's catalog to publication, 

 but the great number of changes in generic assignment of species necessitated by redefinitions of genera 

 prevents any such move until I complete studies on the genera of the world. 



