\\t Cauariiaij Jntumdlagbt. 



Vol. XXXV. LONDON, NOVEMBER, 1903. No. 11 



THE GENUS PODISMA IN EASTERN NORTH AMERICA. 



BY E. M. WALKER, B.A., M.B., TORONTO. 



Podisma (Latr.) is a particularly interesting genus of Melanopli, 

 since it is the only one of that immense group that occurs in the Old 

 World, where, indeed, it is represented by considerably more described 

 species than it is in North America. It is also of interest from its dis- 

 tinctly boreal and alpine distribution, being almost peculiar to high 

 latitudes or altitudes. It is a circumpolar genus, inhabiting the mountains 

 and boreal parts of Europe, Asia and North America, a larger number of 

 species having been described from Europe than elsewhere. 



The North American species are found in two widely-separated 

 regions : the Rocky Mountain region from Alberta to New Mexico in the 

 west, and from North-western Ontario to Maine and south to Pennsyl- 

 vania in the east. It is to the eastern species that the reader's attention 

 will be directed in the present paper. 



Although in some cases Podisma is but narrowly separable from 

 Melatioplus, it is on the whole a distinct type, differing from the lattei 

 chiefly in the widely-separated mesosternal lobes, the interspace in the 

 male being transverse and as wide or nearly as wide as the lobes them- 

 selves, and in the female strongly transverse and as wide as or wider than 

 the lobes. The pronotum is always short and sometimes subcylindrical, 

 with the lateral carinse poorly defined or absent, and the hind margin trun- 

 cate or slightly emarginate, or at most obtusangulate. The tegmina are 

 normally abbreviate, and often entirely absent. Of the North American 

 species, those from the east have no tegmina, while of the western forms 

 these organs are present in all but one species. 



Two species of Podisma have been described from eastern North 

 America, P. glaciaiis, Scudd., from the mountains of New England, New 

 York and Pennsylvania, and P. variegata, Scudd., from specimens taken 

 at Ithaca and Enfield Falls, Tompkins Co., N. Y. Before the description 

 of the latter was published the writer sent drawings to Mr. Scudder of 

 specimens of Podisma taken at De Grassi Pt., Lake Simcoe, Ont., which 

 were pronounced P. variegata, and later on specimens from the same 

 locality were sent to him. On Sept. 12th, 1900, while collecting at North 



