256 BOARD OF AGRICULTURE. 



cles, tliose at the extreme tip being the smallest and placed 

 nearest together. It is 1.15 of an inch in length. 



Habits of the Horse-Fly. — Common as the horse-fly is in 

 summer, little is known of the early stages of the numerous 

 species swarming m our marshes and over our roads. Westwood 

 remarks that " we are indebted to DeGeer for the knowledge 

 we possess of the transformations of this family. The larva of 

 Tabanus hovinus DeGeer is found in the earth, and is an elon- 

 gated, sub-cylindric form, attenuated at each end, especially in 

 front ; it is destitute of feet, 12-jointed, having the head dis- 

 tinct, narrow, elongated, horny, armed with two strong hooks, 

 antenn£e and palpi ; the fourth to the tenth segments have an 

 elevated dorsal papillose ridge used in progression ; the terminal 

 segment is minute and tuberculiform." Mr. B. D. Walsh has 

 found in IlHnois the larva of a species of this genus which is 

 aquatic, living under submerged objects. It is a greenish, 

 transparent worm, cylindrical, 12-jointed, the body being most 

 slender towards the head, which is small, truncate, conical, the 

 anterior part capable of extension, with short, fleshy antennse. 

 There are six pairs of dorsal, fleshy tubercles. On the under 

 side of the abdominal segments are six retractile false legs, and 

 a single and retractile proleg. It is, when disturbed, vigorous 

 and restless, swimming quickly, often elevating the anal slit, in 

 which the stigmata are probably placed, out of the water to 

 take in the air. 



For the knowledge of another species, the Tabanus atratus 

 Fabr., I am indebted to Mr. James Angus, of West 

 Farms, N. Y., who found a pupa in garden soil, and 

 reared the fly from it. This chrysalis (fig. 5,) is 1.40 

 of an inch in length, and .30 of an inch in thickness. 

 It is long, cylindrical, and rather slender, and the tho- 

 rax is no thicker than the abdomen. The head is 

 nearly two-thirds as long as the thorax, and is large, 

 cylindrical, truncated in front, the end being convex, 

 while the whole surface of the head is smooth and 

 FIG. 5. shining. In the middle of the convex end are two 

 thick, flattened tubercles ; just below, is a transverse curved 

 ridge, divided into two portions by the median line of the body ; 

 on each side of this ridge is a low, flattened tubercle. On top 

 of the head, near the anterior end, is a pair of minute tubercles. 



