BIRD LICE, 379 



CASE Docophorus are characterised by two dark-coloured lines, which 

 pass diagonally from the trabeculae to the occiput, and by the 

 segments of the abdomen having a dark-coloured triangular or 

 oblong patch on each side, which very rarely meet in the 

 centre. 



Docophorus icterodes {Nitzsch). 

 Common on ducks, geese, teal, &c. 



Genus Nirmus {Mtzsch). 



Distinguished from Docophorus by the ab- 

 sence of trabeculse, or, if they are present, by 

 their small size and immobility. Mr. Denny, 

 however, admits that while these are admirable 



- . . . _ , • j_ ii Docophorus icterodes 



diamostic sierns for the extreme species at the (from the duck, groose, 



O o i ^(-j J line in length. 



opposite ends of the line, still there are some 

 which have minute trabeculse which belong to the debatable- 

 ground between the two genera, and that it is extremely difficult 

 to decide to which genus these should be referred. 



^s. Nirmus cameratus {Nitzsch).—lZ. Specimens; 14. Enlarged figure of ditto 

 15. Illustrative vignette (black cock and grey hens). 



Infests' the black cock and grouse. 



Nos. Nirmus claviformis.— 16. Specimens ; 17. Enlarged 

 '^~'^' figure of ditto ; 18. Illustrative vignette (carrier 



pigeon). 



Infests pigeons. 



Genus Goniocotes {Btirm). 

 large; posterior margin triai 

 each side ; abdomen broad, no trabeculae 



. Nirmus claviformis ( rom 



Head large; posterior margin triangular on ^^^^^^^^^^^ 



