WERNER MARCHAND 79 



general, oviposits any time during the day, but as a rule in the 

 morning. 



When "one of the larger species" (including Tabanus albimedius) is about to 

 oviposit "it alights on the leaf or blade of grass with its head downwards; it then 

 thrusts the tip of the abdomen forwards under its thorax, and deposits an egg, 

 which adheres to the leaf owing to the sticky substance which accompanies it. 

 The abdomen is then returned to its original position, and as soon as the next 

 egg is ready to be laid, is again flexed, and the second egg is placed at one or 

 other side of the first. In this way three or four eggs are laid on one side of 

 the first and three or four on the other. The mass at this stage has the shape 

 of a V. The fly now moves forwards, and, raising the end of the abdomen to 

 one arm of the V, places a number of eggs down the side until the apex is reached; 

 she then changes over to the other side and deposits eggs all down that arm up 

 to the apex. In the end a raised compact mass of eggs is built up, which, if 

 examined with a lens, demonstrates the precision with which the eggs are placed 

 in reference to one another." 



The larva of Tabanus albimedius has not been described and also 

 not figured, by Patton and Cragg, though they evidently had it 

 under observation. A good characterization of tabanid larvae in 

 general is given, but the differences of the various species are not 

 entered upon. 



Of the larva of this species, by the same authors, dissections have 

 also been made, and detailed illustrations are given of the mouth- 

 parts (Plate 7, Fig. 97), and of the alimentary tract (Plate 7, Fig. 98). 



The figure given of the head shows the mouth appendages: labrum, 

 maxillary palpus, maxilla, antenna, and mandible; also the lateral 

 area of spines behind the antennae. On the figure the antennae appear 

 to be two-jointed, while the authors state that they are three-jointed 

 in all tabanids. 



The figure given of the alimentary tract shows the esophagus, 

 proventriculus, the narrow salivary glands, apparently inserted in 

 the pharynx, the mid gut, hind gut, and Malpighian vessels, four in 

 number. 



Patton and Cragg were the first to publish anything on the ali- 

 mentary tract of a tabanid larva based on dissection. 



Tabanus atratus Fabricius. — A species inhabiting eastern North 

 America, as far west as Colorado, conspicuous by its large size and 



