202 THIRTIETH REPORT ON THE STATE MUSEUM. [90] 



Engr., blanda Haw., super stes Steph., and leucoptera Beck. 

 But the difference of color between our form and the Euro- 

 pean, does not come within the range of variation thus tar 

 shown in any of the spe'cies accepted as common to the two 

 countries. 



These colorational differences have been critically studied 

 by Dr. Speyer, during the comparisons in which he has been 

 for some time engaged, of the identical and closely allied Noc- 

 tuidse of Europe and America, and some of the results of 

 which have been given in a series of papers, four in number, 

 communicated to the EntomologiscTie Zeitung zu Stettin for 

 the years 1870 and 1875. In his second paper on Europdisch- 

 amerikanisclie VerwandtscJiaften, p. 102, these differences 

 (probable climatic modifications) are so admirably presented, 

 that a translation of that portion of the paper, kindly fur- 

 nished for the purpose by Mr. Grote, cannot but prove most 

 acceptable to those engaged in the study of the Noctuidse 

 who may not be able to avail themselves of the original. 



"In the gray and brown colors usual to the Noctuidse, 

 arising from a mixture of black, white and red, the American 

 specimens, as a rule, show less red than the European, and 

 more black. 



" This appears generally in the color of the abdomen and the 

 hind wings ; the brown- gray of the European forms becomes 

 clear gray or blackish-gray in the American. The red cast 

 which shows on the gray under surf ace of the wings of many 

 brown species, especially on the edges, becomes very faint in 

 American varieties, and is even, at times, wanting. The red 

 brown of the back and fore- wings becomes more gray, black- 

 ish or bluish. A stronger mixture of black darkens the colors 

 of many American forms. The ornamentation (such as costal 

 marks and sagittate points) is often made more distinct and 

 coarser ; the transverse lines and discal spots are thrown more 

 into relief by their deeper black defining lines. 



"But, in opposition to this rule, with regard to gray and 

 brown colors, those arising from a mixture of yellow and red, 

 show more red in American specimens ; and where there is a 

 mixture of black with these latter colors, producing a rust- 

 color, the black is less perceptible, as for example, in the case 

 of OrtTiosia ferrugineoides, Hycbr&cia nictitans, Plusia 

 Putnami and Brephos infans. 



"If there is any change in the shape of the wings, it seema 



