504 PExnoMYzoxjinji. 



in the circumference of the suctorial disk. This, again, is not confirmed 

 by the examination of examples. In all of them I count seven points 

 only, and the small suctorial teeth are as distinct as in P. jluviatilis. 

 The examples of P. omaUi are generally a little stouter in general 

 habit than large and full-grown individuals of P. Jluviatilis ; but this 

 is not a specific character, as the individuals, not only of this species 

 but also of P. mnrintis, vary very much in this respect. 



Petromyzon japonicus, Martens, Wiegm. Arch, xxxiv. p. 3, does 

 not appear to me to bo specifically distinct from P. jluviatilis. The 

 dentition in both is extremely similar, only the Japanese example 

 has an additional transverse series of small teeth behind the mandi- 

 bulary tooth. The figure accompanying the description of P. ja- 

 ponicus is incorrect, and I am indebted to Prof. Peters for reex- 

 amination of the typical specimen. 



3. Petromyzon brancMalis. 

 Pride, Sand-piper. Small Lamprey. 



a. Ammocoetes-form. 



Lamproyon ou Lamprillon, Bmdel. De Pise. Iliiv. p. 202. 



Larapetra caeca, Willu^ghhy, p. 107, tab. G 3. fig. 1. 



Petromyzon, no. 3, Ai-tedi, Synon. p. 90, and Gen. p. 64 ; Gronov. 



Zoophyl. p. 38. no. 3(K). 

 Petromyzon branchialis, L. Syst. Nat. i. p. 394 ; Bl. Fisch. Deutschl. 



iii. p. 40, taf. 78. fig. 2 ; Bl. Schn. p. 532 ; Lacep. i. p. 2G, pi. 2. fig. 1 ; 



Turt. Brit. Fdun. p. 110; Gronov. Syt^f. ed. Gray, p. 2. 

 Pride, Penn. Brit. Zool. iii. p. 71, pi. 8, or,ed. 1812, iii. p. 107, pi. 10. 

 Petromyzon ruber, Lacep. ii. p. 90, pi. 1. 



lumbricalis, Palt. Zoogr. Ross.-As. iii. p. 09. 



■ caecus, Couch, in Loud. Mag. Nat. Hist. v. p. ^3, fig. 10. 



Ammoccetes branchialis, (Dtancri!) Cuv. liegue An. ; Nilss. Skand. 



Faun. Fisk. p. 748 ; Finn. Brit. An. p. 104 ; Jenyns, Man. p. 522 ; 



I'arnell, Fish. Firth of Forth, p. 287 ; Yarrel', Brit. Fish. 2nd edit. 



ii. p. 609 ; Selys-Longchamps, Faune BcUje, p. 227 ; Kriiyer, Damn. 



Fisk. iii. p. 1060; Giinth. Fisch. Neckar's, p. 135 ; Ileckel 8r Kner, 



Siisstcasserf. p. 382, fig. 204 ; Gray, Chondropt. p. 14;>. 

 Mud-Lamprey, Couch, Fish. Brit. tsl. i. p. 404, pi. 248. fig. 2. 



(i. Mature form. 



I'etromvzon plaueri, Bl. Fisch. Deutschl iii. p. 47 [taf. 78. fig. 3 ?] ; 

 Bl. Schn. p. 631 ; Lac6p. i. p. 30, pi. 3. fig. 1 ; Osheck, Vet. Akad. 

 JIandl. 1804, p. 181; Blainv. Fauna Fru7iq. ii. p. 8, pi. 1. fig. 3; 

 Jenyns, Man. p. 522 ; Yarrell, Brit. Fish. 2nd edit. ii. p. 607, or, 

 3Ed edit. i. p. 19; Parnell, Werner. Mem. vii. p. 4-16; Ntlss, Skand. 

 Faun. Fisk. p. 747 ; Selys-Longchamps, Faune Beige, p. 226 ; 

 Kriiyer, Danni. Fisk. iii. p. 1060 ; Giinth. Fisch. Neckar's, p. 135 ; 

 Ifeckel <§- ICner, Siisstva^serf. p. 382, fig. 204; Aug. Milller, in 

 Mailers Arch. 1856, p. 32'"5 ; Siehnhl, Siis.swas.<terf. p. 375; Couch, 

 Fish. Brit. Isl. iv. p. 402, pi. 248. fig. 1 ; Blunchard, Poiss. France, 

 p. 517; Onnestrini, Arch. p. la Zool. iv. p. 186. 



uigOT, Jj-icfp. iv. p. 607, pi. 15. fig. 2. 



septocuille, Lac^p. I. c. fig. 1. 



sangui.'^iiga, iMcep. ii. p. 101. 



