CIMEX LECTULARIUS 505 



modified sclerites of the seventh segment ; the sternite of the seventh 

 segment is reduced to two small lateral plates, between which there 

 are two larger plates, also parts of the same segment. Below these 

 four plates, which lie in the same transverse plane, there is a pair 

 of triangular plates, which represent the eighth sternite, and in the 

 interval between these in the middle line another pair of much smaller 

 plates, also triangular in shape, but with their longest sides pointing in 

 the antero-posterior direction. The genital orifice lies between their 

 borders. The anus opens between a small pair of plates (tenth sternite) 

 posterior to these, so that if one counts each pair of plates as representing 

 a segment the abdomen consists of ten in all, of which four are modified. 



The fourth sternite has upon it, about midway between the right 

 lateral border and the middle line, a small longitudinal incision (Plate 

 LXI, fig. 1) which marks the position of the opening 

 into the copulatory pouch, or the organ of Berlese. The c P ulator y 

 If the fourth and fifth sternites are separated by 

 traction, a small and thin oval plate of chitin is revealed lying under- 

 neath the fourth sternite ; in the middle of this, and immediately opposite 

 the upper end of the incision, there is a minute orifice, with a much 

 puckered margin, directed in the antero-posterior plane. It is into this 

 orifice that the organ of the male is inserted in copulation. The genital 

 orifice at the posterior end of the body serves only for the passage 

 of the ova to the exterior. 



The whole of the dorsal surface of the abdomen, and most of the 

 ventral surface also, is covered with serrated hairs, similar to those 

 shown in Plate LXI, figs. 2 and 4. The first and second sternites in 

 both sexes are membraneous in the median area, thus allowing for 

 expansion of the abdominal cavity after feeding. Each unmodified 

 abdominal segment bears a pair of spiracles, which appear as small 

 clear areas on the ventral plates, a little distance from the lateral borders. 



SPECIES OF CIMEX 



Cimex lectularius, L. (Plate LXIII, figs. 1 and 2). Body flattened, 

 reddish brown in colour and covered with fine hairs. Head short and 

 broad ; eyes well developed and of a reddish colour. Prothorax semi- 

 lunar in shape with two rounded horns which extend close up to the 

 eyes ; middle portion of dorsal surface raised, with the sides markedly 

 flattened from a point just external to the level of the eyes. Abdomen 

 rounded and broadest at the level of the third segment. 

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