REHN AND HEBARD 227 



and is circiimorbital in distribution, Palotta and Conocephalus 

 are known from the Old World only, Perissacanthus has been 

 found only in Paraguay, Aphauroyus is known only from Tepic, 

 Mexico, while Anarthropus is known from a species widely dis- 

 tributed in the United States and southern Canada, and from 

 another species from Java. 



The genus is probably found everywhere over the region under 

 consideration south as far as the extremity of the mainland of 

 South America. Lack of material from northern Mexico is 

 much to be regretted. The following forms, treated fully in the 

 authors' first paper on the genus, are unquestionably present in 

 that region, Conocephalus fasciatus fasciatus, fasciatus vicinus, 

 spinosiis, resacensis and strictus; for all of these have been taken 

 in the United States on the Mexican border, and the first and 

 third of these forms are here recorded from farther southward. 

 In addition Co7iocephalus hygrophilns and spartinae will very 

 possibly be found to occur in the salt marsh vegetation along 

 the Gulf Coast, south of the Rio Grande, in Mexico. In 

 desert regions the genus is, as in the United States, doubtless 

 confined to mountains, rivers, streams, lakes and irrigated tracts 

 where a constant supply of water is to be found. The low water- 

 sheds of the Orinoco, Amazon and La Plata systems do not act 

 as controls in the distribution of the species, but the main chain 

 of the Andes appears to afford an absolute barrier. A single 

 species, widely distributed in North America, alone is known 

 from Bermuda. The Greater Antilles have, apparently, but two 

 species, the least abundant, C. insvlaris, peculiar to these islands, 

 the other, C. cinereus, in addition widely distributed from central 

 Mexico to the headwaters of the Amazon. The Lesser Antilles, 

 on the other hand, appear to have but one species, C. saltafor, 

 which is the most widely distributed and, apparently, the 

 most abundant species from Costa Rica southward throughout 

 South America to Paraguay and Eastern Peru. 



The following table illustrates the relationship of the American 

 forms of the genus known to us; showing, in addition to the forms 

 here studied, the position of the forms restricted to North America 

 which have been treated in the previous paper. 



TRANS. AM. ENT. SOC, XLI. 



