THE LARVAL AND PUPAL STAGES OF THE BIBIONIDAE. 



223 



Fully groimi Larva. 



Well grown larvae of Bibio marci were found in considerable numbers during 

 the winter amongst the decaying remains of grass which had been cut the year 

 before, or earlier, and allowed to rot on the ground. They were also found amongst 

 the roots of grass. 



Fig. 3. Fully grown larva of Bibio marci, X 5; sp. \, spiracle of first segment; 

 sp. 12, spiracle of twelfth segment. 



When fully grown the larva is from 20 to 24 mm. in length, and about 2-5 mm. 

 in breadth. Its thickness is rather less than its breadth. The length of the head 

 is about 1-5 mm. and its breadth a Httle less (fig. 3). 



Fig. 4. Head of fully grown larva of Bibio marci, dorsal view, 

 a, antenna ; md, mandible ; mp, maxillary palp. 



53; 



The head (figs. 4, 5) is dark brown and shining, appearing almost black ; the 

 anterior half is somewhat darker in colour than the posterior and bears several 

 long setae. The form of the mouth-parts and antennae is shown in figs. 6-9. The 

 (4183) r2 



