124 THE EARLY STAGES OF TABANID^ 



foot of Quiver Lake, Illinois, over sand, mud, and algas vegetation; 

 at Station I, in the bed of the slough with grass, rushes, and willows, 

 and a very shallow stream of spring water when the river is low; and 

 at Station H, on the Illinois River below Havana, Illinois, where it is 

 narrow, (the east bank steep and sandy, a layer of mud over sand at 

 lower levels, the water quickly deepening, considerable current, a 

 little vegetation; on the west bank mud, steeply sloping, trees but 

 almost no vegetation, decided current), on April 14, 15, and 30; 

 and in Flag Lake, (shallow, muddy, bordered with rushes, thick with 

 floating vegetation), on April 27 — as shown by specimens preserved. 

 The larvae were also taken April 8 and June 15 and 24 in Sand Lake, 

 Lake County, Illinois, and in ponds in Kane and Champaign Counties. 

 I give Hart's description of the larva. 



"Larva. — Length 20 mm., diameter 2.7 mm. Prothorax with lateral shining 

 areas about as long as the dorsal area,^^ striation about the same as that of the 

 upper mesothoracic area, no noticeable central smooth spot, a small one on the 

 lower margin posteriorly; remaining lateral areas a little more finely and closely 

 striate; dorsal and ventral areas of thorax nearly smooth on disk, with basal 

 striae; those of abdomen with moderately close striae, more or less interrupted on 

 disk; all areas more or less shining." 



"Surface whitish, dull pubescent markings very light brown but distinct, annuli 

 narrow, crests of false feet also dull pubescent, their sides striate; lateral stripes 

 of thorax distinct, slender, not dilated posteriorly, lateral edges of dorsal areas 

 of thorax diverging. An opaque dark ring about base of respiratory tube, and 

 another encircling anal prominence, above it usually three light brown spots." 



"Main internal tracheae rather thick and noticeable, subparallel, not strongly 

 sinuate, at least back of the middle. Terminal stigmatal spine often protruded." 



Of Tahanus lineola Hart has obtained three pupas on May 18 of 

 different years. Imagos were obtained from these on May 27, 29, 

 and June 6. The tabanid pupae develop, according to Hart, much 

 more rapidly in hot weather than in cold, and to this fact is probably 

 due the difference in time of emergence. Another pupa was taken at 

 Matanzas Lake on August 24. Hart's description of the pupa follows: 



"Pupa—iVlEite 12, Fig. 149; Plate 13, Fig. 162.] Length 19 mm., diameter 3 

 mm. Light ferruginous brown, shining, abdomen roughly wrinkled and sub- 



^^ I cannot confirm this character from material collected in Princeton, Spring, 

 1917. 



