98 THE EARLY STAGES OF TABANID^ 



The last segment (Plate 4, Fig. 59, c) has the aspect of a small soft textured 

 conical wart; at its end there is a small, elongate protruded horn-Hke brownish 

 yellow piece placed vertically, which I assume to be a spiracle, as a longitudinal 

 fissure is discernible. Under the segment before the last, near the segment 

 preceding it, there is a fleshy prominence, also with a longitudinal fissure in the 

 middle, the anus. 



On the body seven prominent blackish ridges are found situated anteriorly 

 on the fourth, fifth, and the following segments, to the tenth, including the 

 latter. At the sides and below fleshy warts take the place of feet. In con- 

 tracting the rings the interior parts are drawn in. 



The nymph (Plate 4, Fig. 59, b, d), 1 inch in length, of the same thickness as 

 the larva, cylindric excepting the last segment, which is much smaller. It trans- 

 formed into a large horse-fly while I had expected that a large crane-fly would 

 appear. The color was brownish gray; darker at the abdomen and the other 

 parts. The abdomen was eight-segmented; at the posterior margin of each seg- 

 ment was a fringe of long gray hairs. On the last segment at the tip there are six 

 hard horn-like points (Plate 4, Fig. 59, d), by means of which the nymph works 

 its way out of the earth. Head, thorax, and wing cases, or the. whole thoracic 

 region together shorter than the rest. Anteriorly, on the head, there are two 

 small brown tubercles, each of them bearing a hair, probably spiracles. At the 

 side of each tubercle an elongate and equally brownish point, appressed flatly 

 to the head, directed backwards and jointed in the middle, probably the anten- 

 nal sheaths. If the nymph is touched, it carries out worm-like movements with 

 the abdomen. 



Early in July the fly hatched out. The pupal skin splits open dorsally along- 

 side the thoracic shield, and at the sides of the head. Internally, there are in 

 the cuticle of the head two long horn-like spines, the function of which is unknown 

 to me. 



These observations of Degeer are remarkable for their precision. A 

 number of details which have been incorrectly represented in tabanid 

 larvae by several later authors, as the number of segments, position 

 of the anus, etc., have been correctly described. Nothing essential 

 is omitted. Degeer, in 1760, calls attention, like del Guercio in 

 1913, to the similarity between certain tabanid larvas and those of 

 crane-flies, but while the latter is satisfied to state that there is no 

 appreciable difference between them, Degeer's description of the 

 Tabanus larva remains fully characteristic of the group and prob- 

 ably also of the species, though before the larvas hatched, he had ex- 

 pected them to become tipulids. 



