ANOPLURORUM BRITANNLE. 245 



ANTENNA four-jointed, capitate, last joint very large. 



EYES inconspicuous or absent ? 



THORAX of two segments. 



ABDOMEN with ten segments. 



TARSI two-jointed, ungues single, those on the two posterior 



pair of legs sometimes very large and curved towards the 



base of the femur. 



STOMACH symmetrical, somewhat unilateral. 

 LIVER with four free lobes equal in length and breadth. 

 FOOD minute particles of epidermis ? perhaps also hair ? 

 COITUS exercetur femina mari submissa. 



1. GYROPUS OVALIS. (Louse of the Guinea Pig.) 



Plate XXIV. Fig. 1 . 



Pale yellow- white ; head and thorax bright ferruginous, 

 the former transverse, temporal lobes produced ; abdomen 

 large, nearly orbicular ; legs thick, the two posterior pair 

 curved ; ungues long, curved, and strong. 



Gyropus ovalis. Nitzsch. Germ. Mag. iii. p. 304. Burmeister Handbuch 

 ii. pt. ii. p. 443. 



Head broad, transverse, the clypeus trilobate and rotun- 

 date, temporal margin with a large deep sinus on each side, 

 base much produced, occiput concave ; antennae upon the an- 

 terior part of the lateral margin very prominent, the first joint 

 short and cylindrical, second cup-shaped, third large, roturi- 

 date, trigonate, fourth very large and securiform ; prothorax 

 transversely oval, with a depressed transverse line near the 

 centre ; metathorax large, sub-conical, base sub-truncate ; 

 abdomen pale yellow- white, lateral margin and apex slightly 

 ferruginous, nearly orbicular, male with the apex somewhat 

 acute, female with the apex truncate, the first seven seg- 

 ments with the sides dusky ; sutures densely ciliated with 

 hairs ; legs pale ferruginous-yellow, thick and strong, the 



