TRÄGARDH, ON DEVELOPMENT OF CLITOSTETHUS ARCUATUS. 13 



is narrow, cylindrical and bent outwards at a riglit angle at 

 tlie top; it has no hairs. The 2"'i joint is semispherical in 

 outline and nearly twice as wide as it is long, it has 5—6 

 long straight and pointed hairs at the anterior edge. The 

 S*"^ joint is as wide and as short as the 2"'^ one and has a 

 ring of long hairs at the anterior margin. The 4:^^ joint is 

 very large and cylindrical, but obliquely truncated at the top 

 with convex terminal side; it is as long as the 2 + 3 joints 

 and as wide, and is densely clothed with small hairs, the 

 terminal area is densely clothed with minute hairs. The lobus 

 internns is narrow, curved inwards at the top and provided 

 with a dense comb af hyalin bristles, which are as long as 

 the width of the lobus externus. Lobus externus of almost 

 uniform whidth throughout and rounded at the top; it curves 

 inwards in an even curve and bears about 12 straight, 

 pointed hairs and 4 stout, hyalin blunt bristles at the top. 



The labium (Fig. 12, Pl.^I). 



The labial palpi are 3- jointed; the P* joint is very small; 

 the 2°'i joint is as long as the P* and 3^^ one together and 

 club-shaped; it has 3—4 hairs distally and exteriorly. The 3^'^ 

 joint is conical and obtusely rounded at the top. 



