28 BULLETIN 38, UNITED STATES NATIONAL MUSEUM. 



Rhynchagrotis mirabilis. Git. 

 1879. Grt., N. Am., Eut. i, 31) JtjroUs. 



Smoky to deep black ; thoracic disc discoloroas reddish or pale gray, 

 reniforiii coiitrastiug creamy white. T. a. liue much as in mqnda, aud 

 tolerably well marked. T. p. liue indicated by a sparse powdering of 

 pale scales. S. t. liue defined by pale scales; terminal space slightly 

 powdered with gray. A distinct narrow deep black line from base to 

 t. a. line. All from t. a. liue to reniform black, the orbicular absorbeil 

 or appearing as a mere pale point. 



Expands 36 """ ; 1.45 inches. 



Habitat. — Colorado and Arizona. 



An odd species of which I have not seeu a, S . It differs from all the 

 other species save inelegans, by having distinct anterior and posterior 

 thoracic tufts which are rendered prominent by their contrasting coloi*. 

 Yet the species so evidently belongs here by the general shape, that I 

 felt no hesitation iu leaving it as an aberrant member, leadiug to the 

 stellaris type. 



The c genitalia I doubt not will be found to conform in all essential 

 respects to the plaeida type. 



Group EXSERTISTIGMA. 



Front narrow, subequal, scarcely wider superiorly, smooth. Auteuuaj 

 simple, ciliate in the S . Second joint of palpi so clothed as to form a 

 club at tip. Thorax subquadrate vestiture smooth ; a distinct anterior 

 and posterior divided tuft, collar often slightly produced at middle. The 

 genital pieces of S , while referable to the same structural type, yet 

 show considerable variation. The distinguishing feature is a broad 

 slightly excavate corneous harpe, more or less prolonged into a finger- 

 like projection superiorly ; margin sinuate to inferior angle which is 

 more or less distinctly and acutely indicated. From this main shank 

 there arises some distance from the end, a chitinous base, superiorly 

 prolonged iuto a curved process of varying size aud shape. Kefereuce 

 to the figures on Plate ii will better exphiin the structures. Each ex- 

 amined species has some little peculiarity of its own, and no two are 

 exactly alike. 



The primaries are variable in length aud shape, aud run from the form 

 typical in the cvpida group, to that found in the steJIarifi section. In 

 ornamentation they all agree iu the trigonate orbicular which is open 

 superiorly; usually also the costa is more or less distinctly pallid, and 

 as a rule the cell between the ordinary spots is black, or at least darker. 



Closely allied therefore in habitus and esential structural characters 

 to the ciqnda grouj), yet the ornamentation alone, combined, to except 

 mirahilis, with the thoracic tufting, will serve to distinguish it. 



The chief difficulty in dealing with this group has not been in the 

 separation of the species from tlie material at hand, for that was easy, 

 but iu the identiflcatiou of thy species described by Mr. Grote. Some 



