I'ARASITA. 
357 
Three species live on Man; tlieir ova are termed nits. 
In the two following species, the thorax is very distinct from the 
abdomen, is about the same width and of a moderate length. They 
constitute the genus Pediculus properly so called of Leach*. 
P. humanus corporis, De Geer, Insect., VII, 1, 7- Dirty 
white ; immaculate ; emarginations of the abdomen less salient 
than in the following species. It is exclusively confined to the 
body of Man, and increases to a frightful extent in the morbus 
pediculosus. 
P. humanus capitis, De Geer, Insect., VII, 1,6. Cinereous; 
the spaces in which the stigmata are placed, brown or blackish ; 
lobes of the abdomen rounded. On the head of Man, and of 
children particidarly. 
The males of this and the preceding species, at the posterior 
extremity of the abdomen, have a small scaly and conical ap- 
pendage, resembling a string, which is probably the organ of 
generation. 
Hottentots, Negroes, and various Monkeys, eat these Pediculi, or 
are Phthiropagi. Oviedo pretends that these animals abandon the 
Spanish mariners on their way to India as soon as they have reached 
the tropics, but that on their return, when they arrive at the same 
point, they find them in possession of their old quarters. It is also 
said that in India, hotvever filthy be the individual, they are never 
found except on the head. 
At one period the P. humanus was emidoyed by the physicians for 
the removal of ischuria — they introduced it into the urethra. 
Dr. Leach forms a particular genus, Phthirus, of the P. pubis, 
L.; Red., Exp., XIX, 1, which has a Avide rounded body, a very 
short thorax almost confounded with the abdomen, and the four 
posterior feet very stout f. It is commonly called Morpion. It 
attaches itself to the hairs of the genital organs and eye-brows. 
Its bite is Amry severe. 
Redi has rudely figured several other species found on different 
Quadrupeds. That Avhich Ha'cs on the Hog has a A'ery narroAV thorax 
with a very Avide abdomen, and forms the genus HcBinatopinus , 
Leach|; the Pou clu Bu^le, figured by De Geer, Insect., VII, 1, 12, 
jjresents more important characters. 
I'he others — Nirmidia, Leach — such as the 
Ricinus, De Geer . — Nirmus, Herm. Leach, 
Have the mouth inferior, and composed externally of t\A’o lips and 
t\Am mandibles, resembling hooks, ff’heir tarsi are very distinct, arti- 
culated, and terminated by two equal hooks. 
One single species excepted, that of the Dog, they are all exclu- 
* Zool. Miscell., III. 
'f' For those species which live on Man, see the splendid Avork of Alibert on the 
diseases of the skin. 
t Zool. Miscell., CXLVI ; P.suis, Panz., Faun. Insect. Germ. LI, xvi, 1. 
The P. cervi, Panz., Ib., xv, belongs to the genus Melophagus, of the DiptercA. 
