150 CLASS INSECTA. 



or are jihtirophagi. Oviedo pretends to have observed that 

 these vermin, at the elevation of the tropics, abandon the 

 Spanish sailors that are going to the Indies, and attack them 

 again at the same point, on their return to Europe. It is 

 also reported, that in India, however dirty one may be, these 

 animals are never to be found except in the head. 



There was a time when physicians employed the human 

 louse in suppressions of urine, introducing it into the canal 

 of the urethra. 



Dr. Leach forms a proper genus, phtirus, of the louse of 

 the pubis (P. pubis, Lin.), Redi. Expt. xix. 1. ; which has 

 the body rounded and broad, the thorax very short, being 

 almost confounded with the abdomen, and the four hinder 

 feet very strong. Its vulgar designation is crab-louse (Mor- 

 pion, Fr.). It attaches itself to the hairs of certain parts, 

 and to those of the eyebrows. Its bite is extremely strong. 



Consult, for the species which live on man, the excellent 

 treatise on cutaneous diseases by Dr. Alberti, physician to 

 the king. 



Redi has figured, but rudely, many other species which 

 are found on various quadrupeds. That which lives on the 

 pig, has the thorax very narrow, and abdomen very broad. 

 It is the type of the genus Haematopinus of Dr. Leach.* 

 The louse of the buffalo, figured by De Geer, presents more 

 important characters. 



The others, {Nirmidea, Leach,) such as the 



RiciNus, De Geer — Nirmus, Herm. Leach, 



Have the lower mouth, and composed at the exterior of two 

 lips, and two crotchet -formed mandibles. Their tarsi are 

 very distinct, articulated, and terminated by two equal 

 crotchets. 



* Zool. Misc. CXLVI. P. Suis, Panz. Faun. Insect. Germ. LI. xvi. 

 The louse of the stag, Panz. ibid. xv. belongs to the genus Melophagus, 

 of the order of diptera. 



