228 CLASS YII. 



OKEN'S Isis, 1817, s. 881 (with fig.), the same 1818, s. 2080; KNOLZ 

 (seep. -226); BRANDT Mediz. ZooL n. 1833, s. 230 297; MOQUIN-TANDON 

 Monographic des Hirudin6es, &c. 



Amongst the foreign species we note Hirudo zeylanica, found in the 

 Island of Ceylon ; its poisonous bite is followed by very tedious ulcers. 

 TYTLER, Edinl. new Philos. Journ. 1826, p. 375. 



B. Acetabulum of the mouth of a single segment, distinct 

 from the rest of the body by stricture. 



Hcemocharis SAV., Piscicola BLAINV., LAM. Body cylindrical, 

 attenuated forward, with few rings, little distinct. Anterior aceta- 

 bulum slightly excavate, with mouth triangular, edentulous, placed 

 in the bottom towards the inferior margin; posterior acetabulum 

 large, obliquely terminal. 



Sp. Hcemocharis piscium, Hirudo geometra L., ROESEL Ins. m. Tab. xxxn. ; 

 LEO, Ueber einige ausgezeichnete anatomische und physiologische Verhdltnisse 

 der Piscicola geometra, MUELLER'S Archiv. 1835, s. 419427, Taf. xi. This 

 species lives in fresh-water and adheres very firmly to Carp, Tench, &c. 

 It moves like a geometrical caterpillar ; on the back-side of the cephalic 

 disc are four black eye-spots ; copulation occurs in the upright position, in 

 which the animals support themselves on the ventral disc and embrace in 

 form of an X. They lay eggs of a yellow-brown colour, three-fifths of a 

 line long. 



Piscicola respirans TROSCHELL, new species, Archiv f. Naturgesch. xvi. 

 1850. 



Pontobdella LEACH, LAM., Albione SAV. Body cylindraceo- 

 conical, attenuated forwards, with unequal rings. Acetabula very 

 concave ; mouth small unarmed, placed at the bottom of the anterior 

 acetabulum ; posterior acetabulum exactly terminal. 



These animals live in the sea and adhere to different fishes, especially to 

 Bays. Most of the species are beset with nodes or with warts on the 

 rings, which are flatter in Pontobd. verrucosa, BASTER Natuurk. Uitspan- 

 ningen I. Tab. x. fig. II., more pointed in Pontobd. muricata LEACH. In 

 others these nodes are entirely absent, as in Pontobd. lubrica GRUBE ; eyes 

 seem not to be present. 



OKDER III. Setigera. 



Body annulate, provided with setae or with setigerous rudiments 

 of feet. External branchiae in most. 



A. No external organs of respiration (Abranchia). 



Family IV. Lumbricini. Branchiae none. Body provided with 

 setae, without rudiments of feet. 



