222 



r. W. EDWAEDS. 



6. Filaments mucli shorter than the pupa, all of equal thickness, the upper pair 

 shorter than the others ; all four pairs with extremely short stalks : cocoon 

 with " windows " on each side in front 



reptans, L., and var. galeratum, n. 



Filaments about as long as the pupa ; upper pair slightly thicker but no 



shorter than the others ] cocoon without " windows " . . . . 7. 



7. 



Fig. 4. Bases of prothoracic respiratory organs of Simulium pupae, side view, to 

 show branching ; all X 35 : a, ;S^. ornatum ; h, 8. ornatum, var. ; c, 8. ornatum var. 

 nitidifrons ; d, 8. suhornatiim ; e, 8. reptans ; f, 8. morsitans ; g, 8. variegatum ; 

 h, 8. monticola ; i, 8. venustum ; j, 8. tuberosum ; h, 8. argyreatum ; I, 8. latipes: 

 m, 8. aureuni ; n, 8. angustitarsis : o, 8. subexcisum ; p, 8. yerburyi ; q, 8. tredeci- 

 tnatum. 



The four lower filaments arising from a short common stalk at the base ; then 



with longer separate stalks, of which that of the lower pair is the longer 



morsitans, Edw. 



The three upper pairs of filaments separate from the lowest pair at the base 8. 



The stalks of the two lower pairs of filaments usually longer than those of the 



two upper pairs . . . . . . . . . . ornatum, Mg. 



All four pairs of filaments with short stalks of about equal length 



ornatum var. nitidifrons, n. 



