[This parasite has often been a great pest amongst soldiers during long campaigns, especially amongst the Russians during the Crimean War. Vide also notes in Addenda (p. [615]) under “Body, Head and Clothes Lice.”—F. V. T.]
Genus. Phthirius, Leach.
Phthirius inguinalis, Redi, 1668.
Syn.: Pediculus pubis, L.
Male 0·8 to 1·0 mm. in length; female 1·12 mm. in length; colour greyish-white; form subquadrate; the two posterior pairs of legs are strong; the abdomen has nine segments and six pairs of stigmata; and still another pair of stigmata is situated between the two anterior limbs. Eggs pear-shaped, 0·8 to 0·9 mm. in length, 0·4 to 0·5 mm. in breadth, and are deposited in rows of about ten on the hairs.
Fig. 378.—Phthirius inguinalis, Leach: they are distinguished by the larger tracheal trunks originating from the stigmata. Enlarged.
Pediculus pubis, which is found almost exclusively in the Caucasian race, lives on hairy parts of the body, but hardly ever on the skin of the head; the pubic region is its favourite place of abode.