Vol. Xxiv] ENTOMOLOGICAL NEWS 309 



crease in the number of dark scales and the pattern remains 

 unchanged. Often, however, the melanistic process is so com- 

 plete that the markings are entirely obscured. I consider here 

 only the second kind of black coloration, namely melanism 

 affecting the Geometridae. Nigristic forms are products of 

 heat or cold, and they also can be produced artificially by tem- 

 perature experiments. However, the form described above 

 represents the type of a special subdivision of melanistic 

 forms. For the markings have disappeared almost entirely 

 in this case, while in other cases of melanism they remain un- 

 changed. The markings are here not obscured by dark scales 

 as might be supposed, for the coloration is of a dark smoky 

 color and not dense enough to hide markings, if such were 

 present. 



I propose to express this subdivision of melanistic forms 

 (appearance of dark scales, together with disappearance of 

 wing markings) by the collective term "formae melanoticae 

 simplices." 



Nyctobia anguilineata Gr. f. nov. eastmani (Fig. 10). 



Primaries above white. The following markings are present: faint 

 brown basal line, brown median band not very strongly defined, but 

 appearing distinct on account of the light wing coloration; a terminal 

 line of brown dots. 



Secondaries above white and hyaline, becoming slightly dusky to- 

 wards the outer margin ; no markings, except a very faint and minute 

 black dot at the discus near costa. 



Beneath, all wings white and hyaline with no markings, except re- 

 appearance of the minute black dot of the secondaries and this is even 

 fainter than above. 



Head, thorax and abdomen grayish-white, antennae brown. 



One male from West Roxbury, Mass., April 28, 1912; 

 taken by Mr. Walter F. Eastman from a hemlock tree. I 

 take pleasure in naming this form after the collector. 



Type in Mr. Eastman's collection. 



I regard this form as an albino of a form parallel to the f. 

 reiffii Sw. of Nyctobia limitata, and it may be developed 

 through the influence of low temperature upon the pupa 

 shortly before the coloration process of the wings had begun. 



Finally one word may be said concerning the naming of in- 



