IIESPERIDI: THE SPECIES OF IIESJ'ERIA. 1535 



the United States east of tho Rocky Mountains, is found again upon the 

 Pacific coast, but not as yet witliin the intervening area. Thyniclicus 

 brettus is a different kind of instance, being known only along the sea- 

 board, excepting in a single instance west of Lake Michigan. Limochoree 

 manataaqua represents a case extremely similar to that of Eupliyes verna, 

 occupying the same area in the east and found again at the same locality in 

 the west. Tiie repetition of these cases plainly indicates a direct connec- 

 tion between the two widely separated areas. 



But perhaps the most striking instance of all, with the possible exception 

 of Erora laeta, is that of Hesperia centaureae, and it is the more striking 

 from tlic fact that it is a checkered butterfly which no one could possibly 

 overlook, as entirelv different from anvthing else found in the regions where 

 it occurs. This butterfly, which is an inhabitant of extreme northern 

 Europe, was for a longtime known on this continent only from the eastern 

 coast of Labrador, when it suddenly turned up thousands of miles away in 

 the mountains of West Virginia, and within the last twenty-five years or 

 more has been found at several localities in the intervening area, — at Wash- 

 ington, Long Island and the northern borders of Vermont, the first two 

 on low lands, and yet at immense distance from its true subarctic home. 



\\ e have here referred only to the anomalies in the known distribution 

 of the living buttei-flies themselves, for space does not permit more than an 

 allusion to the fact that the mere presence of certain butterflies having their 

 main affinities in far distant quarters of the globe is itself the greatest of 

 anomalies ; but here we evidently touch upon questions into which geologi- 

 cal time enters as an important element and the consideration of which 

 might lead us too far afield. 



Table of the species of Hesperia, based on the imago. 



Extramesial white band of upper surface of wings composed of subcontinuous spots, each of 

 which is much broader than, generally at least twice as broad as, high; hind tibiae and hind 

 coxae of males with no special appurtenances montiTaga. 



Extramesial white band of upper surface of wings wholly discontinuous, the spots no 

 broader than high ; hind tibiae of males with a basal pencil of very long hairs, and bind coxae 

 with a long, cyliiulrical, posteriorly directed, subcorneous process, densely covered with 

 short hairs centaureae. 



The early stages of one of the two species being wholly unknown, no further tables can be 

 constructed. 



