40 OHIO STATE ACADEMY OF SCIENCE. 



CHRYSOPS MOERENS Walker. 



Length 8 to 11 mm. A dark colored species, sides of first two 

 abdominal segments narrowly marked with yellow, that on the second 

 segment encroached upon from behind by a small black triangle. Wings 

 beyond the crossband with a very narrow brown border along the costa; 

 under side of abdomen uniformly black, or at most with suo'gestions of 

 yellowish in patches. 



Female: Frontal callosity black, shining, facial callosity yellow, 

 shining; wings with base, costal cells and crossband, which does not 

 reach the posterior margin, brown or nearly black; the brown margin 

 along the costa beyond the crossband is so narrow as to be nearly obsolete, 

 both basal cells hyaline; the abdominal segments, both dorsally and ven- 

 trally are gray margined behind and dorsally these margins expand into 

 triangles in the middle of the segments. 



Male: Darker colored than the female, a small patch only hyaline 

 at apex of each of the basal cells ; posterior margins and triangles of 

 the abdominal segments less plainly marked than in the female ; the 

 yellow on sides' of the first two abdominal segments variable, that on 

 second segment present in all my specimens and quite constant, but it is 

 oftentimes lacking altogether on the first segment ; this sex usually some- 

 what smaller than the female. ; 



Habitat : Northern Ohio. 



The species is a very common and annoying one at Sandusky 

 through July. The females bite severely and persist in follow- 

 ing our small boats through the marshes, and the hotter the sun 

 the more active the flies. The females oviposit on various kinds 

 of foliage in the marshes, oftentimes several rods from shore, 

 where the water is four feet in depth or more. The eggs are de- 

 posited in a single layer, and a short time after deposition become 

 pure shining black in color. Just how the young from masses of 

 eggs deposited in such deep water grow to maturity and emerge 

 as adults I have not been able to observe ; of course some masses 

 of eggs are deposited very near the shore. The males have been 

 taken in large numbers by sweeping in grass near shore, and on 

 various kinds of flowers which grow in the vicinity. This is the 

 first mention of the male of this species, I have seen in print. 



The large size, the abdomen black ventrally and the very 

 narrow costal margin beyond the cross-band in both sexes easily 

 distinguishes this species from others of its group. 



CHRYSOPS MONTANUS Ostcn Sacken. 



Length 7-8 mm. Face, palpi and base of antennae yellow; the 

 hyaline triangle does not cross the second longitudinal vein but in the 

 majority of specimens reaches entirely to it; the apical spot covers about 

 one half of the second submarginal cell. 



Female : Frontal callosity black ; first basal cell of wing infuscated 

 on basal third and on the narrowed part at apex ; second basal cell hyaline 

 except a slight infuscation at extreme base; the cross band attains the 

 posterior margin entirely filling out the fourth posterior cell; the posterior 



