ENEMIES OF APHIDES. 253 



regular intervals, as in Plagionathiis and Orthocephalus, which are 

 characteristic. The tarsi are three-jointed. 



The Abdomen of the Imago. 

 The abdomen in the Capsida is much softer in its structure 

 than is the case with most other families of the order. In Capsus 

 lanarius it is somewhat short and fairly wide ; the number of 

 segments which may be readily observed does not exceed eight, 

 but the generative segments comprise the representatives of two or 

 three other segments, so that some of the best writers on the 

 Hemiptera give the total theoretical number of segments as eleven. 

 In Capsus the females are provided with a beautiful and strangely 

 constructed ovipositor, contained, when retracted, within a groove 

 formed by a pair of horny ridges on the under surface of the 

 abdomen. In the male, the only external evidence of the organs 

 of generation consist of a pair of " genital styles," which are found 

 at the extremity of the abdomen. 



The Ovipositor. 



This organ consists of four chitinous blades, somewhat broad 

 and 'short, slightly curved and widened towards their points, some- 

 what after the shape of a flat spear-head. The organ is figured on 

 Plate XIV., at Figs. 6, 7, and 8. The two outer blades, a and b, can 

 scarcely be said to form a sheath for the stronger blades within them, 

 but it is more probable that they fulfil the part of lancets, and 

 pierce the surface on or in which the egg is deposited, leaving the 

 central blades only the function of passing on the egg. 



Both pairs of blades are strengthened by a narrow chitinous 

 rib, and towards their extremities the lancet blades are finely ser- 

 rated on the outer surfaces, giving to the edges the appearance of 

 a saw. In C. lanarius also several larger teeth, independent of 

 the serration, are visible on the outer edge, but these I have not 

 observed in any of the other species, which are furnished with a 

 similar ovipositor. The central ribs, which give the necessary 

 rigidity to the ovipositor proper and to the lancets, coalesce in 

 pairs at the base of the organ, and joining beneath it, so as to 

 form a ring, through which the base of the ovipositor proper is 

 attached to its muscular supports, they continue into the lateral 



