34$ THE ANIMAL PARASITES OF MAN 



Gen. Limnalis, Mq.-Tandon, 1826. 



Nearly related to hirudo, but is differentiated by a longitudinal groove 

 on the inner surface of the upper lip of the anterior sucker. The jaws 

 are furnished with over 100 very sharp toothlets. 



3. Limnatis nilotica, Savigny, 1820. 



Syn. : Bdella nilolica, Sav. ; L. nilotica, Moq.-Tandon ; Htemopis (vcrax) 

 Moq.-Tandon, 1826, p. p. ; Hcemopis sanguisuga, Moq.-Tandon, 1846 (nee 

 Hir. sanguis Bergm., 1757). 



This species measures 8 10 crn. 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 varia- 

 tions occur. 



The native place is N. 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, oesophagus, 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 H. granulosa (India) are placed 

 with this genus, and, like' our leech, are also used for medicinal purposes. 



Gen. Hcemadipsa, Tennent, 1861. 



These leeches live on land, and'tneasure 2 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 (H. ceylonica, 

 Bl., and other species). 



2. Rhynchobdellidce, leeches with rostrum. 



These are furnished with a proboscis in lieu of the jaws ; the segment 

 consists of three annulations. 



Gen. Hcementaria, de Filippi, 1849. 



H. officinalis, de Fil. Inhabit Mexico, where they are used for medicinal 

 purposes. 



Gen. Placobdella, R. Blanch. 



PI. catenigera, Moq.-Tandon. Indigenous of South Russia, Hungary, 

 Italy and South France. It is a parasite of the swamp turtle, but frequently 

 attacks human beings. 



