338 STATES OF INSECTS. 



pris and Onthophagus, the anterior tarsi are usually broken 

 off. Out of seventeen individuals of Scarabceus MacLeay 

 in my own, not a single one has a relic of an anterior tar- 

 sus ; and scarcely one in a much greater number of Pha- 

 ncei. The tarsus in question in the nobler sex in Crabro, 

 at least in C. cribrarius and its affinities, is also very short, 

 especially the three intermediate joints ; but at the same 

 time very broad and flat. In the species just named, the 

 external claw forms a kind of hook ; and in the rest it is 

 considerably longer than the other a . The claws, indeed, 

 occasionally vary in the sexes in other Hymenoptera : 

 thus in Melecta Latr., a kind of bee, in the female they 

 are intire, but in the male they are furnished with an in- 

 ternal submembranaceous tooth or process b . In Cceli- 

 oxys conica and others, those of the latter sex are bifid at 

 the apex, but those of the former acute c . In Megachile, 

 the male claw is as in the instance just mentioned, while 

 the female has a lateral tooth d ; and a similar character 

 distinguishes the sexes in the hive-bee e . 



3. The abdomen. This part affords many external 

 sexual characters, whether we consider its general shape; 

 the number of segments that compose it ; its base, mid- 

 dle, or extremity. 



In general shape it often differs in the sexes. Thus, 

 the abdomen of female Tipulce is lanceolate; that of the 

 male cylindrical, and thickest at the extremity f . In 



a De Geer ii. t. xxviii./. 2. 



b Man. Ap. Angl. i. t. v. Apis **, a.f. 10. $ . 11. $ . 

 c Ibid. t. vii. Apis**, c. 1. cc. 17- ? • 18. $. 

 d Ibid. t.Vm.f. 30. e?. 31. ? • 



e Ibid. t. xi. Apis **. e. 1. mas./. 9. t. xii. Apis **. e. 1. fern. /. 9. 

 and neut,/. 22. ( De Geer vi. t. xviii./. 12, 13. 



