TABANID^ OF OHIO. 35 



Habitat : Sandusky, Ohio. Many specimens of both sexes. 



The species is separated from Havidus by the following : The 

 antennae are longer and have the first two segments thicker and 

 the third colored differently at base. The basal cells are more 

 infuscated, the apical spot less clearly defined and the abdomen 

 more uniformly colored. In Havidus the abdomen is distinctly 

 lighter in color at base, but not so in brunneus. The former ap- 

 pears to be southern in its range, while the latter is probably 

 northern. 



Osten Sacken's description of the abdomen and apex of the 

 wing under flaiidus would seem to indicate that he had both 

 species before him. 



The species is abundant at Sandusky from the latter part of 

 June to the first of August, and is an annoying pest in the vicinity 

 of the marshes. It is abundant at any time of day, but appears 

 to be most numerous and persistent in the evening, and its at- 

 tacks are prolonged till almost dark in warm weather. 



CHRYSOPS CALLiDus Ostcn Sackcu. 



Length 7-9 mm. The width of the apical spot is equal to the dis- 

 tance between the costa and the second vein at the distal end of the 

 first vein. First two segments of the abdomen yellow on the sides and 

 this color on the second is not encroached upon by a black triangle. 

 Basal half or more of the venter of the abdomen plainly yellowish but 

 with a dark stripe or some dark spots on the mid ventral line. 



Female : Frontal callosity black ; facial callosity yellow ; both basal 

 cells hyaline; dorsally the abdominal segments with narrow, yellow hind 

 margins which expand into triangles in the middle, none of these triangles 

 extend forward far enough to entirely divide the black of any of the 

 segments. Lateral margins of the segments behind the third black. 



Male : Both basal cells with about the apical third hyaline ; the 

 yellow on the sides of the first two abdominal segments is more promi- 

 nent and the posterior margins of all the segments wider than in the 

 male of moercns. 



Habitat : All parts of Ohio. 



It is exceedingly common all over Ohio during the latter half 

 of May and first half of June, and the females have often been 

 observed attacking horses and cattle. The eggs are laid on foliage- 

 over water along the margins of ponds and canals ; on a previous 

 page in this paper we have described the eggs and the process of 

 oviposition. The males have been taken on flowers and swept 

 from vegetation growing near water. Although the species 

 is- most abundant during the months I have mentioned above, 

 now and then a specimen is seen later, and last summer specimens 

 were procured as late as August 28th, in the northern part of the 

 state. 



