( cxxxii ) 



It would appear that clasping organs are absent in ver)' 

 many if not the majority of the genera of Coleoptera ; the 

 reason of this is obvious ; primarily the facts that the act of 

 mating takes place with the male on the top of the female, 

 that the weight of the insects proportionately is greater, 

 together with the sedentary habits of the order as a whole, 

 would, seem to account for the lack of these organs — prob- 

 ably the dominant factor may be the sedentary habits of 

 the insects, for we find the same position is adopted by the 

 Diptera, and they have strongly and highly developed ex- 

 k^rnal armature ; but here we have an excessively active and 

 highly nervous order, the species of which are light, and very 

 frequently they are very frail creatures to which a well- 

 developed interlocking apparatus M^ould be of the gi'eatest 

 value. Commander Walker, however, informs me that 

 among the Coleoptera he has seen Atomaria mesomehs paired 

 end to end, though whether this is the rule or not he does 

 not know, nevertheless the fact is of great interest, for this 

 species has no trace of any organs except the sedoeagus, and 

 the same is the case with other species of this genus. Many 

 Coleoptera have prominent lateral sensory apophyses, and in 

 a few genera I have found the terminal segment developing 

 into a sort of weak lateral hook, but scarcely such as w^ould 

 form an efficient anchor. Sharp and Muir have shown (Trans. 

 Ent. Soc. 1912, p. 477 ct seq.) the excessive development of 

 the cedoeagus throughout the order, and it is very frequently 

 an organ of great complexity and often of much beauty. 



It is, however, a matter of considerable interest to realise 

 that some Coleoptera have the front leg specially adapted 

 for clasping pm'poses. Dyiiscus marginalis has been observed 

 by Mr. Darlaston to use it thus during the process of mating, 

 the long terminal claws of the tarsus and the peculiar tri- 

 lobed pad, the upper and largest lobe of which has two cushions 

 that evidently act by suction, are admirably adapted to this 

 use. 



Ocyp us f II sea tus, Gr a v . 



The figure shows the lateral apophyses well ; these appear 

 to be sensorv organs. 



