Limnatis nilotica, Savigny, 1820.
Syn.: Bdella nilotica, Sav.; L. nilotica, Moq.-Tandon; Hæmopis (vorax), Moq.-Tandon, 1826, p. p.; Hæmopis sanguisuga, Moq.-Tandon, 1846 (nec Hir. sanguis, Bergm., 1757).
This species measures 8 to 10 cm. in length, and becomes gradually more pointed towards the front; the body is always soft. The back is brown or greenish, and has usually six longitudinal rows (rarely only two or four) of black dots. The abdomen is dark; but numerous colour variations occur.
The native place is North Africa, especially the coastal regions; it is also found in the Canaries, the Azores, Syria, Armenia, Turkestan, perhaps also Southern Europe. It is taken into the mouth with drinking water, and may settle in the pharynx, larynx, œsophagus, and nasal cavities of human beings. This species has also been observed in the vagina and on the conjunctiva. It is equally fond of attacking domestic animals.
Hirudo mysomelas (Senegambia) and Hirudo granulosa (India) are placed with this genus, and, like our leech, are also used for medicinal purposes.
Genus. Hæmadipsa, Tennent, 1861.
These leeches live on land, and measure 2 to 3 cm. in length. About a dozen species are known. They are a veritable scourge to persons in the tropics (Asia, South America), as they attack them to suck their blood. They are able to force their way even under close-fitting garments, so that it is difficult to protect oneself from their assaults (Hæmadipsa ceylonica, Bl., and other species).
Family. Rhynchobdellidæ (Leeches with Rostrum).
These are furnished with a proboscis in lieu of the jaws; the segment consists of three annulations.
Genus. Hæmentaria, de Filippi, 1849.