104 THE EARLY STAGES OF TABANID.^ 



larvae of tabanids or other insects, while the felled trunk enclosed 

 numerous larvae of Tipulidae, Asilidae (Eryx), and some larvas of 

 beetles (Lamellicornia). 



Picard and le Blanc's observations are insufficient for an exact mor- 

 phological description of the larva, but a brief description of the 

 pupa is given, based on the pupal shell left after the hatching. A 

 translation of this description follows: 



Pupa. — (Plate 12, Fig. 136.) Slightly curved inwards ventrally in its posterior 

 part; measures 20 mm. in length, 4 mm. in width, and 3 mm. in height. The 

 anterior part (Plate 13, Fig. 155), extending to the scutellar segment, and com- 

 prising the head, thorax, legs, and wings, is smooth and unarmed, except for some 

 dorsal hairs. The posterior part of the pupa (Plate 13, Fig. 158) is composed of 

 seven segments, surrounded at about the second third from their base with a 

 crown of stiff and unequal bristles. The tubercles described by Surcouf in an 

 unidentified pupa were not observed. The last segment is terminated by two 

 three-toothed tubercles, at the base of which is found ventrally a cup-shaped 

 formation which possibly corresponds to the anus of the larva. The preabdom- 

 inal segment and the first six abdominal segments bear on each side a spiracle 

 placed towards the base of the segment, at the height of the anterior third. The 

 crown of bristles of the seventh segment is incomplete and interrupted dorsally. 



The emergence of the adult causes at the anterior part of the pupal shell a fis- 

 sure which separates it into three wings, two dorsolateral ones and a ventral 

 one of irregular shape. The latter, in the shape of an elongate hexagon of 4 mm. 

 length by 3 mm. width, shows a characteristic ornamentation which can be 

 traced on the figure given. 



At the anterior part two tubercles are found, each bearing a bristle; somewhat 

 below two slight ridges which meet in the median line, further down two doubled 

 tubercles, placed between two triangular thickenings, finally, more posteriorly, two 

 pairs of small tubercles between which two depressions with inner convexities 

 are found. A little in front of the point of attachment of the piece, two lateral 

 triangular expansions are observed. It is probable that the first two tubercles 

 correspond to the antennae of the larva and the others to the mouth-parts. 



These observations show, according to Picard, that certain species 

 of tabanids may have wood-inhabiting larv«, and that their habits 

 are more variable than one would suppose. Picard' s paper is accom- 

 panied by three figures. 



The observations made by Paoli on Graber's organ (page 37) have 

 possibly been made on this species. 



