226 CLASS vii. 



Sp. Nephelis vulgaris, Hirudo octoculata L., Encydop. method., Vers. PI. 51, 

 figs. 5 7 STURM, DeutschL Fauna vi. 2 Heft ; JOHNSON, Phil. Trans. 

 1817, PI. iv. (reprinted in his Further Observat. on the Leech, 1825); this 

 species swallows small worms. 



Trocheta DUTROCHET, Trochetia LAM. (Geobdella BLAINV. in part). 



Branchiobdella ODIER. Body somewhat depressed, with large 

 rings, not numerous. Two horny jaws. Eyes none. 



Sp. Branchiobdella astaci ODIER, Mem. de la Soc. cTHist. nat. de Paris i. 

 1823, pp. 69 78, PL iv. (already observed and figured by ROESEL, Ins. in. 

 PI. LIX. figs. 19 7.2 1 ); Branch, parasita, comp. HENLE, Ueb. die Gattung 

 Branchiobdella, MUELLER'S Archiv. 1835, s. 574, &c. Taf. xiv. 



Hirudo L. (exclusive of several species). Body oblong, sub- 

 depressed, with numerous rings. Three horny jaws. Eyes usually 

 ten. 



Bdella SAV. Jaws not denticulate. Eyes eight. 

 Sp. Bdella nilotica SAV., GUERIN, Iconogr., Ann4l. PI. 4, fig. 10. 



Hcemopis SAV. Maxillae armed with a double row of denticles not 

 numerous. Eyes ten. 



Sp. Hcemopis sanguisorba, Hirudo sanguisuga L., Encydop. meth., Vers. 

 PI. 51, figs. 3, 4, black, grey-green beneath; this species is larger than the 

 common Leech. Commonly two species have been here confounded, 

 which MOQUIN-TANDON places in two different genera: Aulastoma (Hir. 

 sanguisuga MUELL., Hir. Gulo BRAUN, STURM, DeutschL Fauna vi. 2) and 

 Hcemopis (Hir. sanguisuga BERGM., L.) 



/Sanguisuga SAV. Jaws armed with a double row of denticles 

 very slender and crowded. Eyes ten. 



Sp. Hirudo medicinalis L., Hirudo vencesector BRAUN, STURM, Deutschl. 

 Fauna vi. i Heft ; BRANDT u. RATZEBURG, Mediz. Zool. n. Taf. xxvni. 

 fig 8 - 3> 4 > GUERIN, Iconogr., Annel. PI. 10, fig. 3 ; above, blackish -green, 

 with six long stripes spotted reddish and black, beneath olive-coloured with 

 many black spots (four to five inches long). Another species, Hir. ojficinalis 

 SAV., is also used for medicinal purposes, which is yellowish beneath with 

 a broad black edge, without spots, see BRANDT u. KATZEB. 1. 1. Taf. xxx. 

 fig. i; J. J. KNOLZ, Naturhist. Abhandl. ueber die Blutegel, Wien, 1820, 



1 This genus must by no means be confounded with Branchiobdellion EUD., Bran- 

 chdlion SAVIGNY, which like Clepsine and Nephelis has no jaws, but only three project- 

 ing points ; if the semicircular little plates on the same part of the body be really gills, 

 as SAVIGNY says, (CuviER doubts and MOQUIN-TANDON denies it,) then it does not 

 belong to this order. LATREILLE places it near the genus Arenicola. 



