August — December 1SS9.] 



PSYCHE. 



237 



tured, marking the trees and the very 

 twigs on whicli they were at work. 

 Waiting till the leaves were fully grown 

 I found these oaks hoxo^ futilis galls in 

 abundance, but no other species, and 

 comparing the flies I captured with 

 those I got from the bark galls found 

 them to be identical. Of their identity 

 there can be no doubt whatever. 



But I am asked : Do they agree in 

 character with the flies from \\\QfutiUs 

 galls? They do not; and they would, 

 no doubt, be described as a diflerent 

 species. They are many times larger 

 than the futilis flies, and there are 

 other points of difterence. But this va- 

 riation was to be looked for, developed, 

 as the two generations are, under con- 

 ditions so widely different. 



Dr. Adler and other European ento- 

 mologists, who have followed the life 

 history of these insects more closely than 

 I have been able to do, have found that 

 the two generations differ so widely that 

 they have been classed, by those who 

 were not aware of their close relation- 

 ship, not only as two different species, 

 but have actually been placed in diflerent 

 genera. 



I name and describe this insect as fol- 

 lows : 



Callirhytis r ad ids., Bass, (agamous 

 form of N. futilis., O. S.) Head 

 black and opaque, face, cheeks and 

 vertex with short, bristle-like hairs. 

 Antennae very short, with fourteen dis- 

 tinct joints ; the first joint short and 

 thick, the second globular (scarcely 

 ovate) ; length of the third one-fourth 

 less than that of the two preceeding, the 



diameter of eacli from the eighth to the 

 fourteenth inclusive equals tlieir length ; 

 the last forms a very blunt cone. Color 

 of the antennae dark reddish brown, 

 changing gradually to a dull dusky 

 browni towards the apex. 



Thorax black, the punctuation fine 

 and beautifully regular and even. Parap- 

 sidal grooves extending throughout, 

 broad, shining lines over the base of the 

 wings, a narrow but distinct median 

 line from the collare to the scutellum 

 and two parallel lines, one each side or 

 the median line and in close proximity 

 to it, reaching half way from the collare 

 to the scutellum. • 



Scutellum coarsely and irregularly 

 wrinkled, the fovae round, deep and 

 shining. 



Abdomen large, black with brown 

 translucent edges ; second segment very 

 long and with a dense band of yellowish 

 white hairs on the anterior margin, the 

 third segment mostly, and the remaining 

 ones quite concealed. 



Legs: trochanter black, the remain- 

 ing joints very dark cinnamon brown. 

 Claws black, simple. Wings large, 

 hyaline ; principal veins pale brown, 

 others colorless ; radial area broad, the 

 angle of the first transverse vein project- 

 ing sharply into the basal portion ; 

 areolet very small and the lateral veins 

 bounding it entirely colorless. 



Length: body, .15; antennae, 09; 

 wings, .16. 



Those taken in the act of ovipositing 

 are in all respects like those described 

 except that the color of the antennae, 

 legs and w'ings is a trifle darker, — owing, 



