JAPANESE LAND LEECHES. 277 



Hœmadipsa Tennent (1.S61), which is found in Ceylon, India, Burma 

 (1894), and Japan (18(S6), may be regarded as a terrestrial representa- 

 tive of the medicinal leech, being so nearly allied to the latter that both 

 were long known under the common generic appellation of Hirudo. 

 In fact, Hœmadipsa ditfers from Hirudo only in tliose points, that are 

 most likely to be influenced by change of habit. They agree in 

 having three toothed jaws and five pairs of eyes, and differ only in the 

 number of suppressed rings at both extremities of the body. The 

 second genus, Xerohdella von Frauenfeld (1868), is closely allied to the 

 preceding one. It has three toothed jaws, like Hirudo and Hœma- 

 dipsa, but differs from them both in having four pairs of eyes instead 

 of five. This genus is characterised, further, bv the ])resence of a pair 

 of tentacle-like appendages at the anterior extremity of the body. The 

 only species, by which this genus is represented, Xerohdella Lecomtei 

 von Frauenfeld (1868), lias hitherto been found only in the mountain- 

 ous parts of Europe. The third genus, Mesobdella R. Blanchard 

 (1893), is certainly the most remarkable of all the land leeches. It 

 occupies a place in between the two natural divisions of Hiru- 

 dinea. While it agrees with the Gnathobdellids in possessing 

 ten eyes and three denticulated jaws, each of its somites consists of 

 three rings and its intestine is provided with a numl^er of large lateral 

 blind sacs, as is the case in the Rhynchobdellids. This genus is 

 represented, like the preceding one, by only one species, which is a 

 native of Chili. The two remaining genera Cijlicohdella Grube (1871) 

 and LiiudjricoJidella Kennel (1886), both of which are confined to South 

 America and the West Indies, form a group to themselves, in contrast 

 with the remaining land leeches. They are found in the same localities 

 and closely resemble each other externally. They have both no eyes 

 and no jaws. One of them, Luiidiricohdella, has no acetabulum. Their 

 internal organisation shows that they are to be placed in the Family 



