130 Mr. G. C. Champion's Revision of the 



elytra, Maronius and Belotus, the walls of this pit are 

 drawn out into long oblique tubular processes, and in 

 Maronius the aedeagus is asymmetric, and covered by a 

 convex cap; but these genera differ from the Chaulio- 

 gnathinae in the form of the terminal abdominal segment, 

 etc. 



The aedeagus* of the males of the Chauliognathinae is 

 very different in structure from that of the Telephorinae, 

 and owing to the twisted median lobe and the asymmetric 

 lateral lobes copulation must of necessity be lateral. The 

 very stout median lobe and the tegmen appear to be 

 soldered together, but the basal portion of the former is 

 membranous (figs. 1, 9a, 22a), allowing a certain amount of 

 movement when coition takes place. The left lateral lobe 

 (as seen dissected and directed forwards) is usually longer 

 than, and always differently shaped from, the right lobe, 

 the latter being occasionally wanting (C. tripartitus, etc.) ; 

 and its apex together with that of the spoon-shaped 

 terminal portion of the median lobe forms a pair of claspers 

 for grasping the female during the prolonged copulation. 

 The median orifice is on the distal aspect of the main 

 central lobe, and the more or less evaginated soft internal 

 sac is frequently visible in dried specimen-s. The im- 

 movable lateral lobes vary in structure according to the 

 species, and one or the other of them is sometimes bi- 

 or trifurcate at the tip. When the form of these lobes, 

 which can be seen by hfting the aedeagal cap (= last 

 ventral segment of Leconte and the valvular plate of 

 Gorham), is taken into consideration, it affords in many 

 cases a ready means of discrimination between closely 

 allied species. Figures of these structures are appended 

 to the present paper (Plates IV — VIII), that of C. procerus 

 (figs. 44, 44a) being added for comparison with the 

 American forms, t They are taken, and described, from 

 the dissected aedeagus mounted on its ventral surface, 

 with the lobes directed forwards and thus reversed. This 

 is actually the dorsal aspect of the organ, the convex 

 ventral portion, on which aspect the median lobe is mem- 

 branous at the base, fitting into the concavity of the oval, 

 convex, aedeagal cap. 



* Cf. Sharp and Muir, Trans. Ent. Soc. Lond. 1912, pp. 481, 484, 

 485. 



t Cf. Sharp and Muir's figure 139, showing the aedeagus of an 

 unnamed Chmdiognathus ? from New Guinea. 



