NEUEOPTERA PERLINA ACRONEUEIA ABNORMIS. 913 



sented by the female type in the British Museum, is very nearly related, 

 but, according to McLachlan, a different species. 



A specimen (nyrnph) of this species was secured by Dr. J. T. Rothrock 

 in the San Luis Valley, Colorado. 



A species of Chloroperla was also taken, but too much damaged to be 



recognizable. 



ACRONEURIA. 



An abnormal nymph of this genus, probably A. abnormis, was secured 

 at Four-Mile Creek, Lower Park, Colo., by Dr. J. T. Rothrock. In regard 

 to this species the following may be interesting : 



ACRONEUEIA ABNORMIS, Hagen. 

 Perla abnormis, HAGEN, Synop., 17, f. 1. 



This species appears to vary in a very high degree. The late B. 

 Walsh, after repeated observations of living specimens, confirmed variation 

 in size and color, in the reticulation of the wings, and in the number of 

 quadrangular areoles, which are sometimes nearly or altogether wanting ; 

 the shape of the prothorax, and the vulvar lamina of the female, commonly 

 of a constant shape in this family, offer also slight variations in this species. 



The male has usually long and well-developed wings ; however, two 

 short winged males, now before me, seem to belong to this species. The 

 material in my collection of dry and alcoholic specimens, though rich in 

 specimens from different localities, seems to be not yet sufficient to decide 

 the question whether we have here several very closely related species, or 

 simply varieties of A. abnormis. 



Two females from South Montana and a male from Snake River, South- 

 eastern Idaho, collected by Prof. C. Thomas, differ as follows : The colors 

 are darker ; the abdomen yellow beneath, on each side dark brown. The 

 male, in worse condition than the females, is a short winged one ; the shape 

 of the prothorax somewhat different, perhaps only altered by the bad preser- 

 vation. The vulvar lamina of the two females is more produced than usual, 

 covering one half of the following segment ; the apical margin is nearly 

 semicircular, notched very little in one female, and not at all in the other. 



A cast nympha skin, from Eagle River, Colorado, August 30, collected 

 by Lieutenant Carpenter, belongs to a very large species. Length, 33 milli- 

 58 z 



