36 



Order III. BDELLIBEA. 



HiRUDO, Linn. Syst. x. 649. Daly ell, Pow. Great, ii. chap. 1. 



Les Sangsues, Cuv. Reg. Anim. iii. 212. 



Annelides Hirudine^, Savigny, Syst. des Annel. 6 & 105. 



HiRUDiNES, Savigny, Syst. 108. 



Sanguisugaires, Blainville in Diet, des Sc. nat. xlvii. 205 (1827). 



HiRUDiNEA, Blainville in lib. cit. xlvii. 205. Latr. Fam. Nat. 246. 



Moq.-Tandon, Monogr. 2/9. 

 Les Hirudinees, Lam. An. s. Vert. v. 289. 

 HiRUDiNA, Macleay in Murchison's Silurian System, ii. 699 (1839); 



and in Ann. Nat. Hist. iv. 385. 

 Bdellidea, Blainville sec. Diesing, Syst. Helm. i. 415. 

 Myzocephala monocotyla seu Bdellaires, Blainville in Diet. 



des Sc. nat. Ivii. 530, 555 & 556. 

 Annelides suceurs, Milne- Edwards, Elem. Zool. ii. 225. 

 Annelida suctoria, Jones, Anim. Kingd. 189. 

 Annelides suceuses, Audouin Sf M.-Edwards, Litt. de la France, 



ii. 60. 

 DiscoPHORA, Gruie, Fam. Annelid. 28. 



Char. Body elongated, depressed or subcylindrical, annular, the 

 rings narrow, defined by continuous lines, apodous, determinate in 

 number ; the anterior conformed into a more or less distinct sucker, 

 with the mouth in its centre or on its ventral side ; and the posterior 

 forming a terminal circular cupped disc : mouth sessile, with or 

 without denticles or jaws, or with a proboscis : eyes sometimes none, 

 more commonly there are from two to ten on the anterior rings in 

 pairs, sessile and simple : sexual orifices single, anterior and ventral 

 simple pores in the median line : vent opening on the dorsum above 

 the posterior disc. Nervous system a single median ganglionated 

 chain. No special organs of taste, smell, or hearing ; the touch 

 exquisite, diffused, but perhaps more concentrated in the discs. 

 Circulation in vessels, the blood red or almost colourless. No special 

 organs of respiration : intestinal canal chambered, sacculated, and 

 furnished with caecal appendages more or less developed : herma- 

 phroditical. In a more or less strict sense, the Bdellidea are all 

 parasitical and aquatic. They suck the juices of other animals, but 

 a few are zoophagous. They do not reproduce amputated portions 

 of the body. They are oviparous, and protect the ova in horny 

 capsules or in fibro-gelatinous cocoons. The young do not undergo 

 a metamorphosis, and attain maturity slowly. None are phospho- 



