ANOPLURORUM BRITANNIA. 183 



racter. Had it been in my power, I should have been glad 

 to have visited London for the purpose of examining this 

 and one or two other specimens. 



SUB-GENUS VI. ORNITHOBIUS. (Denny.) 



Ornithobius, Denny's MSS. Nirmus, Burmeister. 



SUB-GENERIC CHARACTER. 



Head large, cordate, emarginate ; clypeus obtuse, with two 

 horny acute mandibuliform processes (plate 22, fig. 

 1 c.) ; trabeculcE none ; eyes prominent, near to the 

 anterior margin of the head ; antennce situated about two- 

 thirds from the base, with the first three joints the largest, 

 in the male much the longest, with the first and second 

 joints cylindrical, third acutely produced on the internal 

 side, fourth and fifth small ; prothorax small, flat; meta- 

 thorax large and rotundate ; abdomen elongate and de- 

 pressed. 



1. ORNITHOBIUS CYGNI. (Louse of the Swan.) 



Plate XXIII. Fig. 1. 



White, smooth, and shining, the first six segments of 

 the abdomen with a black spot at the base of the lateral 

 margin, last segment wholly black ; ungues chestnut. 



Pediculus cygni. Linn. Syst. Nat. ii. 1018. 17. Fabr. Syst. Ent. 807. 18. 

 Syst. Inst. ii.480. 21. Stewt. ii. p. 299. Pulex cygni. Redi. Expe. 

 tab. 8. Redi. Oper. tab. 20. The Louse of the Swan. Albin. Aran. 

 76. tab. 48. 



Head with two short fovea in front, and two depressed 

 lines from the eyes to the occiput, and three or four punc- 

 tures on the lateral margin towards the base ; antennae very 

 short in the female ; prothorax much narrower than the 

 head, quadrate ; metathorax transverse, the width of the 

 head, anterior part very rotund, base produced and sub- 



