yellowish quadrangular spots arranged in a regular pattern. The ventral surface is olivaceous or reddish-brown, unspotted. At certain seasons there appears, on the anterior third of the body, a broad belt or clitellus, most apparent on the belly and in the middle of it there is the orifice whence the ova are excluded. The young are greyish, with dusky interranea forming an ill-defined fascia along each side. Müller and Moquin-Tandon have characterized twelve varieties from the peculiar patterns on which the colours are disposed; and four of these Savigny has described as distinct species. I have found three of them in Coldingham Lough. (a) The Whiteadder, Berwickshire, Dr. Johnston. 5. TROCHETA. Trocheta, Moq.-Tandon, Monogr. 308. Dies. Syst. Helm. i. 459. Trochetia, Lam. An. s. Vert. v. 291. Blainville in Dict. des Sc. nat. xlvii. 244. Cuv. Règn. Anim. iii. 215. Geobdella, Blainville in lib. cit. xlvii. 244, & lvii. 559. Char. Body elongate, flattish, smooth, acephalous, composed of numerous subequal narrow segments separated by a simply impressed line mouth large, oblique, with the thick prominent obtuse upper lip curling over it: eyes 8, small, the front row lunate, the hinder one transverse sexual orifices between the 32nd and 33rd, and between the 37th and 38th rings: vent large, semilunate: anal sucker of medium size, attached in the centre, directed ventrally. Ova in coriaceous capsules, free, deposited in moist ground. 1. T. subviridis. Trochetia subviridis, Lam. An. s. Vert. v. 292; 2de édit. v. 523. Hab. Boggy ground, subterranean ditches and runlets. Feeds on the earth-worm. Obs. The specimen in the Museum was, when alive, more than 7 inches long. It is yet fully 6, and an inch in diameter. The dorsal surface is of a uniform dull greenish-grey colour; the ventral a shade lighter, and more muscular. The rings are narrow, nearly equal, marked by a simply impressed separating line, and not crenulate on the margins. The mouth is large, transverse, subtriangulate, with a thick muscular overlapping upper lip, which is somewhat crisped. There is a blackish fascia across the front above the lip, but I can detect no eyes; and Moquin-Tandon says that they are frequently difficult to be seen, and are sometimes absent. About an inch and a half behind the mouth the female aperture is very distinct, but the male one is invisible. The vent is very large; and the sucker is shallow with a thin rim. (a) Regent's Park. Zoological Society. 6. AULOSTOMA. Aulostoma, Moq.-Tandon, Monogr. 312. Pseudobdella, Blainville in Dict. des Sc. nat. xlvii. 246 & lvii. 559. Char. Body elongate, narrowed forwards, depressed, soft, acephalous, composed of many equal segments, the sexual orifices between the 24th and 25th, and the 29th and 30th: penis cylindrical: mouth oblique, suctorial, with the upper lip almost lanceolate and protruded in a semi-ellipse; the gullet with twelve long plaits. Eyes 10, in a curved line: anal sucker rather small, centrally attached with a ventral aspect vent large and semilunate. Ova in a free fibrous cocoon, multiparous. Lacustrine, often resident on the humid margin. Carnivorous. 1. A. gulo. Hirudo maxime apud nos vulgaris, The Horse-Leech or Blood-Sucker, Horsleech, Mouf. Theat. Insect. 323, fig. Hirudines venenatæ, Horse-Leeches, Sibb. Scot. Illustr. ii. 3. 34. Hill, Hirudo sanguisuga, Merret, Pinax, 207. Müll. Verm. i. ii. 38; Zool. de Hirud. 13. Johnson on the Medic. Leech, 30. Templeton in Hirudo vorax, Johnson on the Med. Leech, 62. Hæmopsis sanguisuga, Hardy in Tynes. Nat. Club Trans. i. 96. La Sangsue noire, Blainville in Dict. des Sc. nat. xlvii. 249. Pseudobdella nigra, Blainv. lib. cit. lvii. 560, Atlas Hirudin. f. 1. Hæmopsis sanguisorba, Brightwell in Ann. & Mag. Nat. Hist. ix. 12. Aulostoma nigrescens, Cuv. Règn. Anim. iii. 215. Williams, Rep. Aulostomum gulo, Dies. Syst. Helm. i. 461. B. nigra, "Hirudo elongata, per totum corpus nigerrima," Johnson, Med. Leech, 32. Hab. Stagnant waters: common. Obs. In extension about 4" in length; when contracted somewhat granulous. Dorsal surface of a dark olive-green colour or almost black, ventral surface yellowish-green; but the leech is variable in depth of colouring, and is either prettily and thickly spotted, or sparingly spotted, or unspotted. Anterior pair of eyes approximate, the posterior widest asunder and apart. In some individuals the ventral surface is scarcely different in colour from the dorsal, and in these a yellow line runs along the edges. (a) Islington, J. F. Stephens. (6) Lough in Holy-Island, Dr. Johnston. (c) The Whiteadder, Berwickshire, Dr. Johnston. Fam. IV. HIRUDINIDÆ. Obs. This family is suctorial. Cutting into the skin they suck the blood of vertebrate animals, and only fall away when gorged. The alimentary canal is deeply incised and lobed, with the hinder pair of lobes elongated in an intestinal manner. In these the blood will often remain for days and weeks undigested. They endure long abstinence without any apparent loss of bulk. They are lacustrine, but willingly remain out of the water, where they seem to spend the greater portion of their summer life. They become hidden in winter. The ova are involved in a free sponge-like capsule. 7. HÆMOPSIS. Hæmopsis, Savig. Syst. Annelid. 107 & 115. Moq.-Tandon, Monogr. 317. Diesing, Syst. Helm. i. 462. Hippobdella, Blainville in Dict. des Sc. nat. xlvii. 251, lvii. 560. Char. Body elongate, widening backwards, depressed, of numerous distinct segments, with the sexual orifices between the 24th and 25th, and the 29th and 30th: acephalous: mouth large, with the upper lip protruded and almost lanceolate: jaws 3, small, equal, oval, not compressed, with a few blunt denticles: eyes 10, on a curved line, six approximate on the first segment, two on the second, and two on the third: vent small and round: anal sucker large, obliquely terminal. Ova in a spongy cocoon. Lacustrine. 1. H. sanguisuga, greenish-black on the dorsal, and a yellowishgreen on the ventral surface, marked with irregular spots: eyes indistinct. Length 4"; breadth 5"". Hirudo depressa fusca margine laterali flavo, Linn. Faun. Suec. 364. Hirudo sanguisuga, Linn. Syst. x. 649, xii. 1079; Faun. Suec. 2nd edit. Hirudo sanguisorba, Lam. Anim. s. Vert. v. 291; 2de édit. v. 521. Hæmopis sanguisorba, Savig. Annel. 115. Dies. Syst. Helm. i. 462. La Sangsue de cheval, Blainv. Dict. des Sc. nat. xlvii. 252. Milne- Hippobdella sanguisuga, Blainv. Dict. des Sc. nat. lvii. 561. Hippobdella sanguisorba, Blainv. Dict. Atlas Hirud. f. 2. Egidy, Hæmopis sanguisuga, Moq.-Tandon, Monogr. 318. B. fusca, body almost cylindrical, the back of a very deep brown, unbanded; the margins of the same colour. Hirudo fusca, Blainv. Dict. des Sc. nat. xlvii. 273. Moquin-Tandon, Hab. Lakes and ponds. Obs. The variety is a disputable worm. Blainville inquires if it may not be the Trocheta subviridis. Derheims says that it is found in the north of Scotland, and is rather terrestrial than aquatic in its habits. 8. HIRUDO. Hirudo, Linn. Syst. x. 649. Moquin-Tandon, Monogr. 326. Dies. Sanguisuga, Savig. Syst. Annel. 113. Lam. Anim. s. Vert. 2de édit. Iatrobdella, Blainville in Dict. des Sc. nat. xlvii. 253 & lvii. 561. Char. Body elongate, insensibly widening backwards, plano-convex, composed of numerous narrow equal very distinct segments, margined: acephalous; the oral sucker with an entire thick plaited rim, the upper lip prominent, obtusely lanceolate: mouth large, with three equal compressed jaws, multidenticulate on the cutting edge eyes 10, on a curved line; six on the first segment, two on the third, and two on the sixth, remote from the others: anal sucker rather small, with a ventral aspect, radiatingly plaited: vent minute, round. Encloses the ova in a free spongy cocoon. 1. H. medicinalis, greenish-olive or very dark green or brown, with six interrupted yellowish fascia along the back, sometimes obsolete; the marginal band straight. Length 4-7"; breadth 6"". Hirudo major, Gesner, Hist. Pisc. & Aquatil. 503, cum fig. Hirudo, Aldrov. de Insect. lib. 7. 722, and the fig. p. 765. Willis in La Sangsue, Rondel. Poiss. ii. 169. Hirudo alia parvis tuberculis nonnihil aspera medicinalis, Raii Hist. Hirudines innoxiæ vulgares, Sib. Scot. Illustr. ii. 3. 34. Hirudo depressa nigra abdomine subcinereo, Linn. Faun. Suec. 365. The Leech, Swammerd. Bib. Nat. i. 28. Rep. Ray Soc. Zool. 1847, Hirudo medicinalis, Linn. Syst. x. 649, xii. 1079; Faun. Suec. 2nd edit. (1812). Watson, Disp. inaug. de Hirudine, 12. Blumenb. Man. Sanguisuga medicinalis, Savig. Annel. 114. Encyclop. Brit. xi. 225. La Sangsue, Lesser, Insect. Theol. ii. 181. Milne-Edwards, Elem. La Sangsue médicinale, Blainv. Dict. des Sc. nat. xlvii. 254. Cuv. Iatrobdella medicinalis, Blainville in Dict. des Sc. nat. lvii. 561, Atlas Hab. Lakes and ponds. Obs. There is a series of granules, on a raised line, across the middle of every segment. Mr. Bowerbank has given an elaborate description of the cocoon in Ann. & Mag. N. H. xv. 301. pl. 18, fig. omn. The only British specimens I have seen are those in the Museum Collection; and they may be referred to the variety chlorogastra of Moquin-Tandon. The specimen (6) from Weymouth is manufactured I know not how. It has the shape of a Glossiphonia. When let fall in a plate the sound made is like that which a stone of the same size would produce, and suggests a passing suspicion that the body may be fossil. Its real character is disclosed by an examination of the eyes more especially. (a) Christchurch, Hants, J. C. Dale. (b) Weymouth, W. Thompson. Tribe II. CLEPSINEA, Grube. Fam. V. GLOSSOPORIDE. Obs. These are small and neat leeches, usually so transparent as to permit the disposition of the viscera to be seen without any dissection. They are further distinguished, 1st, by having a cylindrical proboscis capable of being extruded at will from the oral aperture; 2nd, by being more strictly geometric in their mode of progression than other leeches, and capable of contracting the body into a ball E |