366 PROCEEDINGS OP THE ACADEMY OP 



fuscous basal quadrangle enclosing the ocelli, longer than wide and throwing 

 off on each side at tip a small branch reaching the two interocular tubercles 

 which are round ; beneath clay-yellow or luteous obscure ; antennas fuscous, ex- 

 cept joints 2 6 or 8, which are more or less luteous ; palpi fuscous. Thorax 

 one-third wider than long, a little contracted behind, its sides straight, anterior 

 angles slightly, posterior ones much rounded, rugulose, luteous with fuscous 

 markings, or sometimes entirely fuscous. Legs luteous, femora and tibiae vittate 

 above with fuscous ; tarsi and generally the knees fuscous. Abdominal setae 

 clay-yellow, with long hairs ; conspicuously banded with fuscous in their cen- 

 tral portion and fuscous at tip; 9 antepenultimate ventral segment truncate, 

 with a triangular tubercle sometimes apparently bifid at its apex ; <$ last ab- 

 dominal segment small and only visible laterally. Front wings hyaline, with 

 a slight brownish tinge ; veins brown, a little lighter on the costa ; from two to 

 five subcostal apical cross-veins; accessory vein direct; from two to four post- 

 costal cross-veins. Hind wings hyaline, the veins pale, except at the tips. 



Length to tip cf wings 12 IV mill. Alar expanse 21 29 mill. Length of 

 abdomen 2>\ 6 mill. Twelve specimens. I obtained a single specimen at 

 Chicago which has the accessory subcostal in one wing two-branched. In 

 more than fifty Rock Island specimens which I have examiaed, it is one- 

 branched in both wings. The tip of the 8th ventral segment tf is luteous, and 

 conceals the 9th. 



Perla fumipennis, n. sp. Differs from the preceding in the anterior and pos- 

 terior wings being distinctly and equally subfumose, the veins fuscous, and as 

 dark in the hind as in the front wings ; and also in the costa of both wings being 

 yellowish. The head is bright clay-yellow, the spot enclosing the ocelli black, 

 and the thorax is brown-black, immaculate. Three postcostal cross-veins. 



Alar expanse 17 mill. Length abd. 4 mill. One tf specimen. 



\\ Perla. Subgenus D. Differs from the preceding only in the ocelli being 

 three in number. 



Perla elongata, n. sp. $ Differs from the $ of producta in being one-third 

 larger, in the antennae and seta? being fuscous, immaculate, and in the prothorax 

 having a wide clay-yellow vitta on each side the middle, extending outwards 

 on the anterior and posterior margins. The head is clay yellow, with the spot 

 enclosing the ocelli black; subcostal apical cross-veins 2 4; postcostal cross- 

 veins 4 5. 



Alar expanse tf 23 25 mill. Abdomen <^ 5 5J mill. Three tf ; 9 un - 

 knowti. The prothoracic markings resemble those of P. nigrocincta, Pictet, but 

 that species is larger, has only two ocelli, and is, besides, arranged as having 

 the accessory subcostal two-branched. The 9th ventral $ is concealed by the 

 8th, which has at its tip a large, smooth, transversely oval tubercle, with a 

 striated outline, as in $ Acroneuria abnormis. 



1 Perla. Subgenus Chloroperla. 



Chloropbrla bilineata? Say. The epistoma has generally, as Say describes 

 it, "an obscure triangular spot," or is more or less clouded with fuscous, but I 

 have not seen a specimen " with two straight fuscous lines before the discal 

 ones" on the head, as described by Dr. Hagen. Neither are the veins "testa- 

 ceous," as Dr. Hagen describes them, except on the disk and tip of the front 

 wings ; elsewhere they are yellowish-hyaline. For these reasons, and because 

 I believe I forwarded specimens of my species to Dr. Hagen in 1860, and he re- 

 ported them to me as " Chloroperla, new species," I conjecture that my insect 

 is the true bilineata, Say, and that Dr. Hagen has described under that name a 

 different insect, or at all events a geographical race of Say's species. Say in- 

 deed states that " the scutel is bimaculate, spots blackish, placed transversely," 

 which is not the case in any of my specimens, and is not stated to be the case 

 in Dr. Hagen's diagnosis. But this is so contrary to the general style of or- 

 namentation in Perlina, that Say was probably mistaken, and mistook a cloud 

 for two spots. In my specimens the meso- and meta-thorax are luteous, more or 

 lees obscurely clouded with fuscous. 



[Sept. 



