514 CASEY 



ADDENDA. 



I. 



While the preceding revision was under way and in fact 

 largely completed, I received considerable sets of specimens 

 from Warren Knaus, H. F. Wickham and F. H. Snow, impel- 

 ling me to rewrite more than half the tabular statement of Met- 

 oponium and virtually all of Bothrotes^ but advantage was taken 

 of this opportunity to eliminate a number of more or less doubt- 

 ful forms and to suggest more practicable dichotomous charac- 

 ters, so that I am much better satisfied with the result. I have 

 to thank my colleagues for thus adding materially to the pres- 

 ent knowledge of the various groups. 



In response to my request, Mr. Champion very kindly sent 

 me all the Central American and Mexican species which were 

 at his disposal, and, with great generosity, placed a number of 

 them permanently in my collection. The importance of this 

 in permitting a direct comparison between the tropical and 

 Sonoran species can well be understood ; it adds a great deal to 

 the usefulness of this revision. It is especially gratifying to 

 observe that the genera proposed above for our fauna, hold per- 

 fectly good for the Mexican species, although naturally a few 

 additional genera are required for some of them. In definitely 

 rejecting the generic name JEmmenastus , it became necessary 

 to know the tropical North American species, in order to assign 

 them properly, as all but one were described under that title in 

 the " Biologia." By help of the representative forms sent me, 

 serving as a key, the following generic dispositions are sug- 

 gested for the numerous species described by Mr. Champion : — 



Eurynietopon brevicolle is assignable to the genus Telahis. 



Emmenastus chiriquensis, belli, alattis, salvini, mtermedtus, 

 longicornis, variahilis, canaltculatiis, brevipennts, solitarms, 

 and rotundicollis, may be placed in the genus Armah'a, which 

 seems to be peculiar to the hot and generally low country 

 bordering the Gulf of Mexico and the Caribbean Sea, a re- 

 gion climatically wholly distinct from the dry elevated So- 

 noran regions supporting the majority of the genera. Of the 

 species mentioned, variabilis, chiriquensis and belli are before 



