Order II. BDELLOMORPHA. HIRUDINEA PLANERINA, Moquin-Tandon, Monogr. 386. Char. Body oblong, flattened, exannulose, smooth and lubricous, acephalous: no eyes: mouth sessile, edentulous and eproboscidean, in the front margin or underneath it, and, usually, with a small suctorial disc (bothria) on each side: posterior extremity with a large circular disc or with six to eight small pedunculated discs. Intestine with an anal aperture at the posterior extremity of the body. Nervous system consisting of two lateral ganglionated cords originating in two cerebral centres placed widely apart. Monoecious or dicecious; the sexual apertures lateral and forwards. Marine parasites of fish and mollusca, infesting the outer surface, and sucking their fluids. The ova are capsulated when excluded, and are attached by a filiform peduncle. The development is unknown. No species is phosphorescent nor iridescent. The British genera may be arranged as follows: Suborder I. CRYPTOCŒLA. The intestine branched, planarian. Monœcious. * POLYCOTYLEA. Posterior sucker multipled. 1. Octobothrium. ** MONOCOTYLEA. Posterior sucker undivided. 2. Entobdella. Sucker granulous and armed with two bicuspidate hooks. 3. Capsala. Sucker radiate with a central disc. 4. Nitchia. Sucker crenulate on the rim with a central disc. 5. Udonella. Sucker plain, without appendage. Suborder II. RHABDOCELA. The intestine undivided, cestoid. Diœcious. 6. Malacobdella. 31 II. BDELLOMORPHA. I. CRYPTOCELA. Fam. I. ONCHOBOTHRIIDÆ. ONCHOBOTHRIIDE (-), Baird, Entoz. Brit. Mus. 39. POLYCOTYLA, Blainville in Dict. des Sc. nat. lvii. 569 (1828). Obs. The body is somewhat pear-shaped, but flat, and broadest at the posterior end, which is furnished with several small suckers in pairs on the margin. 1. OCTOBOTHRIUM, Leuckart, 1827. Octobothrium, Nordmann, Mikrograph. Beitr. i. 76; and in Lam. Char. Body somewhat oval or lanceolate, acephalous: mouth subterminal: suckers pedunculated, eight, separate, with four mobile membranous valves. 1. 0. palmatum, lanceolate, produced in front into a short neck; suckers on a cylindrical pedicle, spreading in a palmate fashion. Length 7-12""; breadth 2-21"". Octobothrium digitatum, Rathke in Nov. Act. Nat. Curios. xx. 242 (1843), tab. 12. f. 12-15. Rep. Zool. Ray Soc. 1847, 472. Diclidophora palmata, Dies. Syst. Helm. i. 417. Octodactylus inhærens, Dalyell, Pow. Creat. ii. 262. pl. 36. f. 1, 2. Hab. "Infests the gills of the ling, to which it adheres with considerable tenacity."-Dalyell. Descr. "It is of a thin and flattened form, extending nine lines in extreme length, by about two in the broadest part. One extremity dilates into two portions, to the right and left, each composed of four tentacular-looking organs, a line in length. The remainder of the body tapers downwards, much like that of the common Planariæ. A longitudinal internal cavity seems to consist of a larger and a smaller compartment; besides which numerous pinnate organs also occupy the substance of the body. The colour of the whole is bluish-grey. The body being remarkably thin, soft, and flexible, it applies closely to its site, with some adhesion; and the two anterior portions clasp the rib of the gills in their fold. They have little other motion than slightly extending and contracting."-Dalyell. Fam. II. CAPSALIDE. TRISTOMIENS, E. Blanchard in Ann. des Sc. nat. viii. 321 (1847). Obs. The mouth is inferior and not terminal. On each side, and a little above it, there is a small sucker (bothria); and on the hinder extremity a large sucker with a ventral attachment and aspect. The cerebral ganglions are placed a little in advance of the oral aperture. 2. ENTOBDELLA. Entobdella, Blainville in Lam. An. s. Vert. v. 295 (1818). Phylline, Lam. An. s. Vert. v. 295. Baer in Nov. Act. Curios. xiii. 674. Moquin-Tandon, Monogr. 391. Diesing, Syst. Helm. i. 426. Epibdella, Blainville in Dict. des Sc. nat. xlvii. 259, & lvii. 567. Char. Body obovate; the front subtriangular, with two oblique marginal linear bothria; the mouth inferior, with a semicircular thickened rim sucker sessile, hemispherical, with a reflected margin, the concave surface rough with rowed granules, and the centre armed with two horny four-hooked clasps. 1. E. hippoglossi. Tertia pediculorum species, Bast. Opusc. Subs. II. ii. 99. tab. 8. f. 11 (1765). Hirudo hippoglossi, Müll. Zool. Dan. Prod. 220. no. 2669; Zool. Dan. ii. 18. tab. 54. f. 1-4; copied in Encyclop. Meth. pl. 52, f. 11-14. Fabr. Faun. Grænl. 322. no. 302. f. 8. Turt, Gmel. iv. 71. Baer in Nov. Act. Acad. Cæs. Leop. Nat. Cur. xiii. 678. pl. 32. f. 5, 6. Phylline hippoglossi, Lam. An. s. Vert. v. 295; 2de edit. v. 526. La Sangsue de l'Hippoglosse, Blainville in Dict. des Sc. nat. xlvii. 269. Tristoma hamatum, Rathke in Nov. Act. Acad. Cæs. Leop. xx. 238. Hab. The parasite of the Holibut (Hippoglossus vulgaris). Obs. Body ovate, flat, thin, lubricous and semitransparent, so as to permit the vessels and interranea to be seen distinctly; and of these the most conspicuous are the testes, which form two large round white spots in the centre of the body. The sucker is very large and subpedicellate, rough, with tubercles excepting on the upper side which is smooth; and it is also armed with two pairs of elongate spinous teeth so placed as to form by their union a sort of oblong or horse-shoe-shaped space running from the inferior margin to the centre of the disc. (a) Berwick Bay, Dr. Johnston. (b) Ireland, Brit. Mus. (c) No locality nor name attached. 3. CAPSALA, Bosc, 1811. Capsala, Blainville in Dict. des Sc. nat. lvii. 568. Moquin-Tandon, Tristome, Cuv. Règn. Anim. iii. 265. Baer in Nov. Act. Curios. xiii. Tristomum, Diesing, Syst. Helm. i. 428. Char. Body suborbicular or oblong, flat: head with two suborbicular marginal or frontal bothria: mouth anterior, between the bothria: sucker inferior, sessile, saucer-like, seven-radiated, with a small central disc: female aperture below the mouth: male organ filiform, behind the vulva on the left side of the body. 1. C. rudolphiana, suborbicular, emarginate behind, foveolate underneath; bothria frontal, suborbicular; sucker with a membranous plaited margin. Length 5-9""; breadth 5-10"". Tristoma coccineum, Rudolphi, Syn. Entoz. 123 & 428. tab. 1. f. 7, 8. Yarrell, Brit. Fish. ii. 353; 2nd edit. ii. 468, vign. W. Thompson in Ann. & Mag. Nat. Hist. xx. 175. Phylline coccinea, Schweig. Handb. 474. Capsala coccinea, Blainv. Dict. des Sc. nat. Ivii. 569, Atlas, f. 11. Tristoma molæ, E. Blanchard in Ann. des Sc. nat. viii. 326 (1847). Hab. On the short Sun-fish (Orthagoriscus mola), not confined to the gills, on which I have not found them. They adhere to every part of the skin. 4. NITSCHIA. Nitzchia, Baer in Nov. Act. Curios. xiii. 675 (1826). Diesing, Syst. Char. Body oblong, flat: head continuous with the body and furnished with two oblique linear marginal bothria: mouth between the bothria, frontal: sucker sessile, cupped, with an inflected crenulate rim and a small central disc: female aperture beneath the mouth penis filiform, below the vulva. J. N. elegans. Nitzchia elegans, Baer in Nov. Act. Nat. Curios. xiii. 660. tab. 32. D Nitschia elongata, Moq.-Tandon, Monogr. 394. Tristoma sturionis, E. Blanchard in Ann. des Sc. nat. viii. 329 (1847). Hab. The gills of the Sturgeon. Found on Acipenser acutirostris, Parn., taken on the coast of Scotland by Dr. Melville. 5. UDONELLA. Udonella, Johnston in Loud. Mag. Nat. Hist. viii. 498. Dies. Syst. Char. Body subcylindrical: head cuneate and truncate, with two oblique marginal oblong bothria: mouth between the bothria, with a short bell-shaped proboscis encircled at the orifice with a double series of papillæ : sucker terminal, sessile, urceolate: sexual apertures ventral and forwards. 1. U. caligorum. Udonella caligorum, Johnston in Loud. Mag. Nat. Hist. viii. 497. f. 45. W. Thompson in Ann. & Mag. Nat. Hist. xv. 320. Dies. Syst. Helm. i. 427. Dalyell, Pow. Creat. ii. 13, & i. pl. 66. f. 11. Hab. Parasitical on the Caligus of the Holibut. II. RHABDOCELA. Fam. III. MALACOBDELLIDÆ. BDELLOMORPHES, E. Blanchard in Ann. des Sc. nat. xii. 275 (1849). Char. Body flattened, exannulose, smooth, with a circular saucershaped sucker at the posterior extremity. Mouth anterior, marginal, edentulous, minutely papillose: intestinal canal simple, with a vent above the sucker. There is no heart, but the circulating system is well developed and copiously ramified. The respiration is cutaneous. The nervous system is bilateral. The sexes are separate; and the female is oviparous. 6. MALACOBDELLA. Malacobdella, Blainville in Dict. des Sc. nat. xlvii. 270; ibid. lvii. 566; and in Cuv. Règn. Anim. iii. 217. Blanchard in Ann. des Sc. nat. iv. 373 (1845), and viii. 142 (1847). Diesing, Syst. Helm. i. 445. Xenistum, E. Blanchard in lib. cit. 142. Char. Body oval or oblong: sexual orifices towards the front: mouth in a frontal emargination, villous internally: sucker attached at the centre, unarmed, large. |