Chap. X.] COLEOPTERA. 361 



but no use can at present be assigned to them. It is a 

 highly-remarkable fact, that although the males do not ex- 

 hibit even a trace of horns on the upper surface of the 

 body, yet in the females a rudiment of a single horn on the 

 head (fig. 21, a), and of a crest [b) on the thorax, are plainly 

 visible. That the slightest thoracic crest in the female 



Fig. 21.— Left-hand figure, male of Onitis furcifer, viewed laterally. Eight-hand 

 figure, female, a. Rudiment of cephalic horn. b. Trace of thoracic horn or 

 crest. 



is a rudiment of a projection proper to the male, though 

 entirely absent in the male of this particular species, is 

 clear : for the female of JBuhas bison (a form which comes 

 next to Onitis) has a similar slight crest on the thorax, 

 and the male has in the same situation a great projection. 

 So again there can be no doubt that the little point (a) 

 on the head of the female Onitis furcifer, as well of the 

 females of two or three allied species, is a rudimentary 

 representative of the cephalic horn, which is common to 

 the males of so many lamellicorn beetles, as in Phaneeus, 

 fig. 17. The males, indeed, of some unnamed beetles in 

 the British Museum, which are believed actually to be- 

 long to the genus Onitis, are furnished with a similar 

 horn. The remarkable nature of this case will be best 

 perceived by an illustration : the Ruminant quadrupeds 

 run parallel with the lamellicorn beetles, in some females 

 possessing horns as large as those of the male, in others 

 having them much smaller, or existing as mere rudiments 

 (though this is as rare with ruminants as it is common 



