No.iuo. NORTH AMERICAN NOCTUtDAE—SMtTB AND DTAR. 69 



occidentalis are allied in sexual structure to each other and to lobeliae; 

 pmipercula and vinnula are much more nearly allied to tritona and grisea, 

 while fraffilis- stands pointing to fimeraUs. haniameUs, and f/risea, with 

 indications toward connecta or tritona. 



Morula is easily known by its large size, its discolorous yellow thoracic 

 disk, and the yellowish shades in the primaries. 



Occidentalis is very .siniiliar, but much smaller, and the thoracic disk 

 is not yellow or otherwise discolored. In the structure of the male 

 chispers the species differ little. In occidentalis the process from the 

 superior margin is reduced to a small angulation, while in morula it is 

 a Hat triangular ])r()cess. 



Paupercula might pass for a small occidentalism but it has a reddish 

 shade, and the black streak from the base to the transverse anterior 

 line is very heavy, and has a small spur or angle inferiorly as if the 

 line had started to divide, and in this character it agrees with vinnula 

 and all the species that have the same general type of genital structure. 

 This seems at first sight like a very small character; but it is constant 

 within specific limits, and all the species with similar male claspers 

 have this spurred or broken basal streak. Unfortunately, some of the 

 species with a diffuse streak sometimes have a similar spur, so that the 

 character is not satisfactory for isolating just this group. 



Vinnula is unique by its glistening white vestiturc, which is marked 

 by bluish, brown, or mossy-green shadings. All the transverse lines 

 are well developed, and there is also a very distinct median shade line. 



Fra</ilis is unique. The wings resemble the albarufa-hamamelis type, 

 the ground color is smoky brown or blacUish, and the very strongly 

 dentate black median lines carry contrasting white accompanying 

 shades. Altogether it is easily separable from all others in the section, 

 to which only its superficial characters refer it. 



Laetijica, furcifera, hasta, manitoha^ thoracica, and strigulata agree in 

 a general resemblance to the preceding series, but have the ordinary 

 spots distinctly tied or connected by a black streak or dash or curved 

 line. Of these the last-mentioned two have a discolorous thoracic 

 dorsum and a tendency to strigate maculation, while all the others are 

 normal in this res])ect. All the species grouped here are allied in geui- 

 talic structure and, except for the strigate forms, resemble each other 

 closely. 



Laetifica differs from the others of the series by the pale, milky- white 

 primaries, in which it agrees with occidentalis. The species has been 

 confused with furcifera which it does not resemble at all, and with 

 occide7italiN, with which small, obscurely marked examples may be con- 

 founded. These small specimens, however, in which the connecting 

 mark between the ordinary spots is sometimes wanting on one or both 

 sides, have the secondaries very dark, smoky brown, and the black 

 markings of the primaries much thicker and more prominent than in 

 occidcntaiis. 



