SCUDDER. NORTH AMERICAN TRYXALTNiE. 51 



gined with black laterally ; the male tegniina are shorter, generally much 

 shorter than the abdomen, with rare exceptions as long as the abdomen, 

 instead of being at least as long as, in macropterous forms considerably 

 longer tbau the abdomen, the vena plicata joining the vena dividens 

 before the middle or fading at some distance before the middle, instead of 

 running free past the middle of the tegmina. In general it is more 

 heavily marked, has shorter tegmina and slenderer antennae. In the 

 female the tegmiua are but little longer than the head and pronotum 

 together, sometimes no longer. It should at least be distinguished as a 

 race; future collections in the intermediate regions will probably show 

 more clearly whether it should be regarded as wholly distinct. 



7. PSOLOESSA AND STIRAPLEURA. 



In his Revision of the North American Tryxalinze (Proc. Dav. Acad. 

 Sc, VI.), McNeill placed these two genera side by side at the end of his 

 series. Later, in my Preliminary Classification of the same subfamily 

 (Psyche, VIII.), I placed them at some distance apart, Psoloessa among 

 the Phlibostromae and Stirapleura in the Scyllinae. This change of mine 

 was wrong and came from incorrect observation of the foveola? of the 

 vertex (a distinction on which I placed a wider reliance than McNeill), 

 for in Psoloessa they are partially visible from above, their plane being 

 twisted feebly in relation to that of the margin of the vertex, so that while 

 they are visible from above on their inner half, they are not so on their 

 outer half. The other features of Psoloessa show that it belongs to the 

 Scyllinae, and I would restore it to the immediate vicinity of Stirapleura, 

 to which it is very closely allied. 



The table given by me for the separation of the genera of Scyllinre may 

 be altered by substituting the following for the final paragraph relating 

 to Stirapleura (Psyche, VIII. l'.JI): — 



Pronotum constricted in the middle, the prozona slightly the shorter; lateral 

 carina? percurrent, more or less divergent in front and strongly divergent behind. 

 Foveolse of vertex visible from above only on the inner half; lateral carinas of 

 pronotum anteriorly but little or at least not strongly divergent, being gently 

 arcuate on the prozona ; lateral lobes of prozona feebly or not marked above the 

 middle with obliquely disposed short lunate carinules . . . Psoloessa Scudd. 

 Foveolae of vertex visible from above throughout their length ; lateral carina? of 

 pronotum very strongly divergent in front as well as behind, being strongly bent- 

 arcuate on the prozona; lateral lobes of prozona more or less conspicuously 

 rugose-carinate obliquely above the middle Stirapleura Scudd. 



