NATURAL SCIENCES OP PHILADELPHIA. 211 



mediastinal vein is opposite the petiole ; the mediastinal cross-vein is very 

 near its tip (the distance is slightly variable in different specimens ;) the great 

 veinlet varies its position (as in D. liber t a;) the upper discal cross-vein is 

 generally arcuated. 



Twenty-three tf and 9 specimens. Trenton Falls, N. Y. ; Berkeley 

 Springs, Va., and Quebec, Canada, (nob.) 



D. d i s t a n s . Very like D. s t u 1 1 a , but mediastinal cross-vein separated 

 from the tip of the mediastinal vein by a distance about equal to the length 

 of the first externomedial vein. The thorax is less shining, and appears 

 slightly yellowish sericeous ; length, lin. 2^3. 



I have 6 (^ and 2 ) specimens, all taken in Florida in March, 1858. 



Besides these specimens I brought five others from the same locality, distin- 

 guished from the former by the absence of the discal areolet, which is open, and 

 by the shortness of the petiole, which is not longer than the great cross-vein, 

 and originates at some distance beyond the tip of the mediastinal vein ; 

 the position of the mediastinal cross-vein is like in D. distans. Among 

 these five specimens there is a ^ and a 2 which I caught in copulation ; and 

 as they agree in the above mentioned characters, it would prove, perhaps, 

 that these are not merely accidental, but specific differences. 



D. pubipennis. Fusca, thoracis disco fusco-nigro, antennis palpisque 

 nigris, stigmate cinereo ; areolis apicalibus sparse pubescentibus ; long. lin. 

 3-3^. 



This species is also very like D. s t u 1 1 a , but it is easily distinguished : 

 1st, by its size, which is a little larger; 2d, by its color, which is darker, 

 especially on the thorax ; 3d, by some peculiarities in the neuration of the 

 wings ; the mediastinal vein reaches considerably beyond the origin of the 

 petiole ; the cross-vein is near its tip ; the distance between the cross-vein 

 and the origin of the petiole is about equal to the length of the discal areolet ; 

 the two cross-veins, which divide the stigma transversely, do not form an almost 

 straight line, like in D. s t u 1 1 a ; the lower cross-vein is arcuated, and ad- 

 vances a little towards the tip of the wing ; the apical part of the wing is 

 finely pubescent, which pubescence does not reach the central cross-veins. 



Eleven male and 9 female specimens, caught in May, 1S59, at Relay House, 

 (near Baltimore.) Five of these specimens (3 <^ and. 2 2) have the discal 

 areolet open ; one of them has it imperfectly closed. 



D. immodest a. Pallide silacea, thorace vitta fusca, abdominis tergo 

 infuscato, alis hyalinis, stigmate pallido, areola discoidali aperta ; long. lin. 



Proboscis pale, palpi infuscated, antennae fuscous, pale at base, front infus- 

 cated. Thorax ochraceous, paler on the pleura? ; collare and prsescutum with 

 a brown stripe in the middle which does not reach the scutum; halteres pale, 

 knob dusky ; feet pale tawny, coxas and basis of femora pale yellow : tips of 

 tarsi duiker. Tergum infuscated ; ^forceps pale. Wings with a slight yel- 

 lowish-cinereous tinge ; stigma elliptical, pale ; the mediastinal vein joins the 

 costal nearly opposite, or a little before the origin of the petiole ; mediastinal 

 cross-vein separated from the tip of the mediastinal vein by an interval a little 

 longer than the stigma; stigmatical cross-vein generally in a line with the 

 tip of the subcostal vein ; sometimes it recedes a little, and then the tip of 

 the subcostal is arcuated towards the radial vein. 



Washington, Trenton Falls (nob.) ; Maine, (Mr. Packard.) 



Twenty-five $ 2 specimens. 



This species is not unlike the European D. modest a, which, however, 

 generally has a discal areolet, its absence being an exception ; on the con- 

 trary I have not found as yet a specimen of D. immodesta with this 

 areolet closed. 



1859.] 



