118 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



Hind wings pale fuscous with white fringes. Thorax and head gray, 

 being composed of black and white scales. Abdomen pale fuscous. 

 Fore wings pointed at apices, with straight costal margin. Wings 

 hoary beneath. Expanse 30 mil. 



Habitat — Nevada; from Dr. J. S. Bailey. In color and ornamenta- 

 tion, this species resembles the genera Morrisonia and Actinotia. In its 

 present position, it comes nearest to 0. chandleri. 



The collection before me contains the following species of Jsoctiddm: — 



Agrotis saucia (Hiibn.). 

 One specimen, "Manitou, July 15". 



Agrotis auxiliaris Grote. 



Two specimens, " Pike's Peak"; one (apparently accidentally stained) 

 is also labeled " Manitou, at light, July 14 ". This species was originally 

 described from Colorado. Specimens from Texas have been since re- 

 ceived. The form originally described is strongly marked, dark-colored, 

 with the stigmata and sometimes the costa whitish or gray. The three 

 specimens determined above belong to this typical form. Two other 

 specimens in the present collection belong to a form of this species, first 

 collected by Mr. Jas. Ridings in Colorado, and described by me in the 

 Proc. Acad. N. S. Phil., 1875, 422. In this variety, which I call agrestis, 

 the ornamentation is not contrasted, the color is paler, the stigmata are 

 not filled with gray, and the insect bears a certain resemlilance to A 

 messoria Harr. The two specimens in the present collection of this 

 form are ticketed "Pike's Peak''. The primaries above are shaded 

 with brown. 

 Agrotis atro-purpurea Grote. 



Through the kindness of Mr. S. H. Scudder, I have been able to com- 

 pare my material with the specimen of tessellata in the Harris collection, 

 now in the museum of the Boston Society of Natural History. Harris's 

 species is shown to be the equivalent of maizi of Pitch, as I previously 

 considered it in my check-list, November, 1875. Mr. Mead has collected 

 the typical tessellata in Colorado, his specimen being numbered "58". 

 The present form may not prove ultimately specifically different. Spec- 

 imens from Albany (Lintner, No. 3707) and the Bast agree with one in 

 the present collection, ticketed "Denver, June 27", in being blackish, 

 with a purple cast, darker and smaller than tessellata ov cam2)estris^ with 

 the lines obliterate and the stigmata x>icked out by gray scales. The 

 same gray scales mark the lines as far as these are visible. The black 

 filling on the cell is distinct. This completes the separation of four 

 closely-allied forms, tessellata, atro-pmjmrea, campestris, and alMpennis. 

 Campestris seems to be generally regarded as a valid species, and pos- 

 sibly of this albipennis is only a variety with white secondaries. In the 

 task of separation of closely-related forms, we have to test differences 

 and agreements at first by their persistency, in considering the advisa- 

 bility of bestowing a fresh name on groups of individuals. 



