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TEXT-BOOK OF ENTOMOLOGY 



appendage, and in that of Aglia tau it forms a long, prominent, 

 sharp spine. In the cockroach, both Cholodkowsky and Haasc 

 maintain that the tenth abdominal segment is suppressed in the 

 female, the tergal portion being fused with the suraiial plate (the 

 latter in this case, as we understand it, being the remnant of 



Vl - 



PP" 



mu 



mu 



FIG. 206. Copulatory organ of a weevil, Rhychopharus phmnicin, seen from above. A , vl, 

 the lobes united into a capsule ; pp, torn membrane which connects the capsule with the 9th ab- 

 dominal segment; ej, ejaculatory duct. B, the same seen from the side; mu, end of the muscle 

 of the penis. C, the same as B, without the capsule ; on, opening of the ejaculatory duct (ej). 

 Other letters as in A. 



the eleventh segment of the embryo). As to the nature of the 

 middle jointed caudal appendage in Thysanura and May -flies Hey- 

 mons has satisfactorily shown that it is a hypertrophied portion 

 of the suranal plate, being in Lepisma but a filamental elongation 

 of the small eleventh abdominal tergite. 



B 



vlu 



bl 



FIG. 20T. A, penis (pn) of Cardbus hortensis: bl, wrinkled membranous vesicle; rl.n. the 

 valves; g, part of 9th segment. B, end of penis of the same, enlarged ; on, cleft-like opening : also 

 a wrinkled vcsicli-. us at f>/. This and Figs. 203-205 after Kolbe. 



At the base of the suranal plate of locusts (Acrydiidae) is the sur- 

 anal fork or suranal furcula ( frrn/(i xitj>r-ii<tlix, as we have called 

 it) (Fig. 88, 89, .0- 



The podical plates or paranal lobes. Tn the cockroach and other 

 insects, also in the nymphs of Odonata, the anus is bounded on 

 each side by a more or less triangular plate, the two valves being 



