June-Sept., 1919.] 



Bezzi : Rhodesiella. 



177 



c. Arista quite bare, wings infuscated or even hyaline. 



21. R. bicolor Becker (1910, p. 431) German East Africa. 



22. R. annulata Becker (1910, p. 432) German East Africa. 



23. R. kovicsi Becker (1913, p. 158) Abyssinia. 



It is not certain that all the above listed species are valid and 

 distinct, or whether they belong to one or different genera. 



Since the genus RJiodesiella is widely spread over the tropical 

 countries of the Old World, its presence in tropical America may be 

 suspected. Indeed, Becker (1912, p. 129) has stated that the 

 Brazilian Onychaspidium sexdentatum Enderlein ( 191 1, p. 196, fig. 4) 

 is a species of Rhodesiella (Meroscinis) ; but Enderlein (1913, p. 

 361) contends that his genus is a sufficiently distinct one, even believ- 

 ing that my African genus Elaphaspis, 1912, may be the same. More- 

 over, Enderlein at the same place (1913, p. 361) has said that 

 his own Leptopeltastes longiscutellata ( 191 1, p. 229) from Brazil is a 

 Rhodesiella (Meroscinis) ; he also says (pp. 361-362) that the 

 Oriental Meroscinis meijerei and M. tibiella both belong to his Brazil- 

 ian genus Coryphisoptron (Discogastrella). 



It is interesting to note that in the subfamily Botanobiinoe, the 

 species having spinous tubercles on the scutellum increase in number 

 from the temperate to the tropical countries, and are represented by 

 vicariant forms in the Oriental, Ethiopian and Neotropical Regions. 

 While the cosmopolitan genus Crassiseta (and in Europe the nearly 

 related genus Myrmecomorpha = Elachiptera s. str.) is the only one 

 which has species in the Palasarctic and in the Nearctic Regions, 

 there are in the warmer parts of Asia, Africa and America numer- 

 ous forms in which the scutellum shows a very extraordinary shape, 

 or bears very long spiniform tubercles. In the following table these 

 forms are enumerated, region for region, and going from those 

 with less developed scutellar tubercles to those in which this feature 

 is more intensively marked. 



Oriental Region. Ethiopian Region Neotropical Region. 



Crassiseta. Crassiseta. Crassiseta. 



Rhodesiella. Rhodesiella. Leptopeltastes 



Thyridula. Coryphisoptron. 



Prionoscelus. Laxobnthmis. 



Nomba. Enderleiniella. 



Epicelyphus. Pentanotaulax. 



Discyphus. Elaphaspis. Acanthopeltastes. 



Dactylothyrea. Cyrtomomyia. Onychaspidium. 



