PETROMYZONTID^E. 359 



surface where the water was about four feet deep, and was struck by a fisherman 

 under the impression that it was a mullet. Found also in the Shannon ; also in 

 Dublin Bay and Liffey (Ball). 



It is usually seen from about 20 to 30 inches in length ; and has been recorded 

 from Devonshire 3 feet long, and from the Severn, at Gloucester, 37 inches long 

 (Holland) and up to about 5 lb. weight. The specimen figured is a female 

 36 inches long, from the Severn. 



2. Petromyzon fluviatilis, Plate CLXXIX, fig. 1. 



Mustda, Auson. Mosell. v, p. 107. Mustela fluviatilis minor, Belon. p. 75. 

 Lampetra parva et fluviatilis, Rondel Pise. Fluv. p. 202 ; Aldrov. p. 581 ; Jonston, 

 p. 117, t, xxiv, f. V), t. xxviii, f. 10, 11 ; Willughby, lib. iv, p. 104, t. G2, fig. 1 

 and G3, f. 2; Ray, Synop. Pise. p. 35; Rutty, Nat. Hist. Co. Dublin, 1772, i, 

 p. 351. Lampetra subcinerea, Salvian. fol. 63a. Petromyzon, sp. no. 1, Artedi, 

 Synon. p. 89, Genera, p. 64 and Species, p. 99 ; Gronov. Miss. Ich. no. 114 and 

 Zoophyl. no. 159 ; Klein, Pise. Miss, ii, p. 29, t. i, f. 3. Lesser Lamprey, Pennant, 

 Brit. Zool. (Ed. 1776) iii, p. 79, pi. viii, and (Ed. 1812) iii, p. 106, pi. x. 



Petromyzon fluviatilis, Linn. Syst. Nat. i, p. 394; Bloch, Ich. pi. lxxviii, fig. 1, and 

 Hist. Nat. p. 658, t. lxxviii, f. 1 ; Bonnaterre, Ency. Ich. i, p. 1, pi. i, f. 2; Gmel. 

 Linn. p. 1514 ; Bl. Schn. p. 531 ; Donovan, Brit. Fish, iv, pi. lxxx ; Tnrton, p. 110 ; 

 Pall. Zoo. Ross. -As. iii, p. 06 ; Ekstrom, Fische Morko, p. 267 ; Flem. Brit. An. 

 p. 163; Jenvns, Man. p. 521 ; Parnell, Wern. Mem. vii, p. 444; Yarrell, Proc. 

 Zool. Soc. 1831, p. 133, Brit. Fish. (ed. 1) ii, p. 454, c. fig. (ed. 2) ii, p. 604 (ed. 3) 

 i, p. 28 ; Templeton, Mag. Nat. Hist, 1837 (2) i, p. 413 ; Johnston, Berwick. N. F. 

 Club, 1838, i, p. 176; Swainson, Fishes, ii, p. 338; Nilss. Skand. Fauna, iv, 

 p. 745 ; Richards. Faun. Bor.-Amer. Fish. p. 294 ; Selys-Longc. Faun. Belg. p. 226 ; 

 Kroyer, Danm. Fisk. iii, p. 1042, c. fig. ; Heckel and Kner, s. w. f . p. '377, f. 202 ; 

 Siebold, s. w. f. p. 372 ; Schlegel, Dieren Neder. p. 205, pi. xxi, f . 4, 5 ; Gronov. ed 

 Gray, p. 1 ; Thompson, Nat. Hist. Ireland, iv, p. 265 ; Blanehard, Poiss. Franc. 

 p. 515 ; Canest. Fauna d'ltalia, Pesc. p. 31 ; Giinther, Catal. viii, p. 503; Collett, 

 Norges Fiske, p. 219 ; Houghton, Brit. F. W. Fishes, p. 195, c. fig. ; Fecldersen, 

 Ich. Dan. p. 94; Giglioli, Cat. Pesc. Ital. p. 55; Malm, Fauna, p. 632; Moreau, 

 Poiss. de la France, iii, p. 604. 



Petromyzon argenteus, Bloch, t. ccccxv, f. 2 ; Bl. Schn. p. 532, t. cii, f. 1. 



Petromyzon prioha, Lacep. i, p. 18. 



Petromyzon jtirce, M'Culloch, West. Isles, ii, p. 186, pi. xxix ; Gray, Catal. 

 Chond. p. 139. 



Petromyzon nigricans, Lesueur, Trans. Amer. Phil. Soc. i, p. 385 ; Storer, Mem. 

 Amer. Acad, ix, 1867, p. 253, pi. xxxix, f. 6 ; De Kay, New York Fauna, Fish, 

 p. 381, pi. lxxix, f. 247 ; Gray, 1. c. p. 139. 



Lampetra fluviatilis, Gray, 1. c. p. 140, and Proc. Zool. Soc. 1851, p. 237, 

 pi. iv, f. 2 ; White, Catal. p. 144. 



Petromyzon omalii, Van Beneden, Mem. Ac. Belg. ii, 1857, p. 549, f. 1-3, xx, 

 1865, p. 46 and xxxviii, 1870, pi. viii ; Malm, Fauna, p. 635. 



Lampem and silver lamprey, Couch, Fish. Brit. Isles, iv, pi. 395, 400, pp. ccxlvii, 

 f. 2. 3. 



The first two-thirds of the body cylindrical, subsequently compressed. Eye 

 rather larger than a branchial oritice. The nasal opening is situated rather in 

 front of the eyes, on the top of the head. Teeth a single one in the maxilla, in 

 the form of a ridge, having a conical cusp at either end ; the mandibular tooth a 

 crescentic ridge with about seven conical cusps ; tongue with a transverse cutting 

 tooth, having a median conical cusp. Two or three teeth having two or three 

 cusps on either side of the gullet. Small teeth in the inside of the sucking disk. 

 Fins an interspace separates the two dorsal fins, the anterior of which is the 

 lowest, while the second is united to the caudal. Skin smooth. Colours bluish, 

 often glossed with bronze and purple along the back, silvery on the sides and 

 beneath ; sometimes obscurely streaked. A dark stripe passes backwards from 

 the eye along the gill-openings. Dorsal and anal fins with a dark mark in their 



