6OO ANOPLURA 



sufficient general resemblance to warrant the belief that the parts 

 in the two may ultimately be shown to be also morphologically 



similar. If Meinert be correct, this 

 view will, however, not prove to have 

 any foundation. He considers that 

 morphologically the mouth of the louse 

 has no similarity to that of the bug ; 

 the protrusible parts in the former he 

 considers to be modifications of epi- 

 pharynx and hypopharynx ; and the 

 rod-like structures to be hypopharyngeal 



envelope into different from the setae of bugs. 1 He 



which the beak can be with- -j T - J-J.-L/^J r 



drawn; d, head of the beak, considers Lice to be a distinct Order of 

 with crown of spines ; g, Insects for which he proposes the name 



labrura ; h, delicate tube Q- i i 



pro traded (very rarely seen 51pnunCUlata. 



in this state) ; m ' t unpaired The alimentary canal and nervous 

 system resemble those of Mallophaga 



more than they do those of Hemiptera. The oesophagus leads 

 into a large stomach bilobed in front ; at the posterior extremity 

 of this there open the four Malpighian tubes, and behind these 

 there is a well-marked small intestine. The nervous system 

 consists of a cephalic ganglion and of three other closely approxi- 

 mated ganglia, the posterior one the larger. It remains 

 doubtful whether or not the first of these three ganglia is the 

 infra-oesophageal one. 2 



The species of lice, so far as known, are not numerous, some 

 six genera and about forty species being all that are recorded ; 

 they occur on various kinds of mammals, including some that live 

 in water. Seals have a genus, Ecliinophthirius, peculiar to them. 

 Monkeys are specially liable to be affected by lice ; the genus 

 that chiefly occurs on them is Pedicinus, a very distinct one, in 

 which there are only three instead of five joints to the antennae. 

 Perhaps the most remarkable louse is Haernatomyzus elepJiantis, 

 that of the elephant ; it has a long proboscis in front of the head. 

 As a rule each species of louse is confined to one species of Mam- 

 malia, or to very closely allied forms. Man is said to be infested 



1 Ent. Meddel. iii. 1891, p. 82. 



2 Cf. Graber, Zeitschr. wiss. Zool. xxii. 1872, p. 165, and Landois in the same 

 Journal, xiv. 1864, p. 24. 



