224 MONOGRAPHIA 



provided. It is true the Bittern and Heron have this pecu- 

 liarity, upon which we find examples of both Lipeurus and 

 Colpocephalum, but upon the Turkey, Domestic Fowl, 

 Ducks, Geese, Pigeons, and the Eagle, which frequently 

 swarm with their peculiar Lipeuri, and the Corvidse, which 

 in like manner have such multitudes of Colpocephalum, 

 and of Menopon, no extraordinary apparatus for this purpose 

 is seen, and again the Goatsucker has the comb-like claw, 

 but whose Louse is very rare, and not belonging to the above 

 genera, which fact is still more opposed to this theory. Mr. 

 Swainson very justly remarks, " To suppose that Nature 

 has given to one or two families of Birds the exclusive power 

 of freeing themselves from an enemy, which in like manner 

 infests all birds, is preposterous." The latter part of this 

 assertion, however, requires qualifying, as all Birds are not 

 alike infested, that is as to numbers, or as to the kind of 

 parasites, vide p. 173, in which we find 8 species of lice, &c. 

 and no peculiar provision made for their eradication. 



10. MENOPON NIGRO-PLEURUM. Denny. 



Plate XX. Fig.l. 



Chestnut, shining and pubescent ; prothorax ob-conical, 

 with a transverse, and four semi-oblique sulci ; abdomen 

 broad, sub-ovate, with black spots on the lateral margin. 



Head sub-triangular, with a depression in front, and a 

 blackish reniform spot before each eye, base slightly con- 

 cave ; eyes very small and flat ; prothorax ob-conical, with a 

 fovea in the anterior part, and a transverse and four some- 

 what oblique sulci ; mesothorax very small and narrow ; 

 metathorax wider than the head, transverse, lateral mar- 

 gins oblique, base convex ; abdomen large, broad, somewhat 

 abruptly ovate, lateral margins of the first six segments with 

 a black spot, underside thickly pubescent ; legs pale chest- 

 nut ; femur thick, the anterior pair sub-angular. Length $. 



This species is rather widely spread. I have found it 



