NOKTH AMERICAN NEUROPTERA 201 



Little has been done to elucidate the sternal characters of the 

 Perlidse ; yet I think that a close study of them will serve to better 

 define the characters of the genera in this family. There are two 

 groups of genera according to the position of the anterior coxse 

 one group where these coxte are approximate and directed more 

 downwards ; the other group where the coxae are widely separated 

 and directed more laterally. To the former group belong Ptero- 

 narcys, Leuetra, Nemoura, Tceniopteryx and Arsapnia. To the latter 

 group are the genera Perla, Chloroperla, Dictyopteryx, Acroneuria 

 and Isopteryx. Capiila has the fore coxae separated, but not as fa)- 

 as in Perla, but the hind coxse are widely separated. 



Pteronareys has the hind coxte well separated, and between them 

 is a transv^erse depression with a hole at each end ; between the 

 middle coxae is a triangular depression. 



Perla has no such depressions, but there are slits near the coxae ; 

 the hind coxic are widely separate. I am inclined to think this large 

 genus can be divided on sternal characters into two or more genera. 



In Leuetra, Nemoura and Tceniopteryx the hind coxae are much 

 closer than in other genera ; I think these will form a tribe. In 

 Chloroperla and Isopteryx the hind coxae are well separated. 



CHRYSOPID.E 



IVIeleoina iiiexicaiia n. sp.— Head pale greenisli, a black dot each side 

 of nioutb and a black line under the eyes ; palpi lineate with black : anteunse 

 pale yellowish throughout; thoi-ax green, a broad median yellowish stripe, a 

 black dot at each anterior angle of prothorax ; legs pale yellowish : abdomen 

 greenish, brownish towards tip ; wings hyaline, veins pale green, many of the 

 transversals, especially on basal part of wing, marked with black in the middle, 

 pterostignia scarcely visible. A horn between antejinse of %, , longer than broad, 

 broader at the tip than in the middle, tip broadly emarginate, each corner 

 pointed, the median part bent at right angle and extending to surface of head, 

 basal joint of antennie concave on inner margin, second and third joints not 

 curved as in 31. slo^sonse ; wings rather long, scarcely pointed at the tip, venation 

 similar to that of other species. Length 20 mm. 



One Z from Amecameca, Mexico, June (Barrett). 



Differs from 31. signoretti Fitch, in pale antennte and smaller 

 horn, etc. ; from M. slossome Bks., in pale dorsal stripe, simple 

 antennae, etc. 



Chrysopa erytlirocepliala n. sp.— Pale yellowish: he-wl reddish, a 

 black dot each side near base of labruni ; abdomen blackish, legs and antennte 

 pale; wings greenish, veins mostly greenish, brownish on middle of costal cross, 

 veins, on the gradate veinlets, and on some veiulets toward base of wing, ptero- 



TRANS. AM. ENT. SOC. XXV. (26) JANUARY, 1899 



