( 453 ) 



XI. Bcscrijiiioois of JVenj Species and a New Genus of South 

 American Eumolpidse, with Eem-arhs on some of tlie 

 Genera. By Martin Jacoby, F.E.S. 



[Read Octolier 3rd, 1900.] 



Dii. Horn, in his monograph of the North American 

 Eumolpini (Trans. Am. Ent. Soc, xix. 1892), says in his 

 introductory remarks: — "The Eumolpini are by no means 

 an easy group to study. While the genera seem fairly 

 well defined as to facies, permanent and sharply limited 

 characters for their definition are not readily found. In 

 fact, practical experience and a certain amount of empirical 

 knowledge are important factors here as well as in many 

 other places in the Coleoptera." 



I can quite endorse his remarks, but may add, that in 

 the study of the group, the difficulties as to the described 

 species or at least a great many of them are much 

 augmented on account of the authors not mentioning the 

 sex they have been describing. In no other group of the 

 Phytophaga is this more essential for the recognition of 

 the species than in the Eumolpini, nor is the definition of 

 the sexes very difficult as a rule ; the males have in nearly 

 every instance the anterior tarsi distinctly dilated or are 

 otherwise distinguished, while the females very frequently 

 have a more transverse thorax and more strongly punctured 

 and often costate elytra. On account of this non-observ- 

 ance or ignorance of the sexes, authors have frequently 

 described both as different species, and it is certainly 

 remarkable that Lefevre, Avho made the Eumolpini his 

 special study, has in many instances neglected to state the 

 sex, and has often given a totally insufficient description 

 of a few lines, so that many of his species are unrecognis- 

 able by his descriptions. I have tried to avoid this in 

 regard to the material now before me, and hope that at 

 least the species described in this paper will be recognised 

 with comparative ease ; all of them are contained in my 

 collection, but it is quite possible, that some may be 

 identical with previously, but insufficiently, described 

 species, which a comparison with the types only can 

 decide. 



TRANS. ENT. SOC. LOND. 1000. — PART IV. (DEC.) 31 



