G6 BULLETIN 38, UNITED STATES NATIONAL MUSEUM. 



Genus PERIDROMA Ilbu. 



Common to the species united umler this term are the following 

 characters : All the tibia^. spinose, fore tibiie rather heavily armed but 

 scarcely abbreviated ; front smooth ; thoracic vestiture consisting of 

 mixed scales and hair; antennai of male simple, or ciliate merely; 

 primaries regularly widening outwardly, apex i)roducetl or rectangu- 

 lar, not rounded. Two groups are united under this term, separable 

 as follows : 



Thorax with disfmctly divided anterior and posterior crests, primaries (uiite evi- 

 dently produced at apex Group sauci a. 



Thoracic tufts not divided, apex of primaries not so distinct Group incivis. 



Saucia may be considered the type of this genus, which contains a 

 not too diverse assemblage of si)ecies, more particularly characterized 

 iii the remarks under the group headings. The assemblage is related 

 rather to the Old World species, but in the incivis group a closer ap- 

 j)roach to the more peculiarly western forms is noticeable. 



Group SAUCIA. 



This group is characterized by spinose fore tibia, smooth front, simple 

 or merely ciliate male antennae and distinctly crested thorax. The crest 

 is usually distinct, extending the full length of thorax, and evidently 

 divided; rather more prominently so anteriorly. The primaries are 

 moderately large, the apices acute, somewhat extended, outer margin 

 oblique. Except rudens and j^ellucidalis, the species are well sized and 

 have a robust appearance peculiarly their own. The normal noctuidous 

 markings are traceable in all species, but often the transverse lines are 

 more or less indefinite or indistinct. The $ genitalia vary greatly, 

 and agree only in that the clasper is single, simple, and curved. The 

 harpes are very different in shape, but afford no bases for grouping the 

 species. 



The species are not difficult to distinguish. Occulta, prccjixa, astricta, 

 and (jrandipennis are large species, with the thoracic tufting least 

 marked. The three lirst named had been placed in the genus Uurois, 

 but I fail to discover any character which allies these species with 

 pressa and prasina, save the size and a general agreement in wing form. 



Occtdta is easily distinguished by its large size, the ashy gray pri- 

 maries, and blackish secondaries. At first glance it is not unlike 

 Acronycta in appearance, but the resemblance is superficial merely. 

 The genitalia of the S are characteristic. The clasper is long, curved, 

 corneous, nearly as long as the harpe, dilated at the base, and slightly 

 so toward the tip. The harpes are long, semi-corneous, the tip 

 straightly cut, the upper angle only slightly prominent. Pnvjixa is 

 smaller, but resembles occulta in the color and general raaculation of 

 the primaries. The secondaries are, howe\er, pale fuscous, instead of 

 black. A single ? only has come under my notice. Astricta is nearly, 



