Marstpohranchs of the Order Hyperoartu. 201 



1-6. Adult, 120-220 mm. Transylvania. C. G. Danford, Esq., and 



(types of the species). J. A. Harvie-Brown, Esq. 



7-12. Larvfe, 95-185 mm. „ „ 



13. Adult, 210 mm. R. Sebes. C. G. Danford, Esq. 



7. Entosphenus. 



Entosphenus, Gill, Proc. Ac. Pliilad. 1862, p. 331. 



Disc without radially arranged series of teeth, but with a 

 marginal series of small teeth, an anterior group of teeth, 

 3 or -1 enlarged teeth on each side, and a posterior series of 

 small teeth, parallel to the marginal series, connecting the 

 last pair of enlarged lateral teeth. A single broad bicuspid 

 or tricu.^pid supraoral lamina ; infraoral lamina cuspidate. 

 Anterior lingual lamina v/ith a single transverse denticulated 

 ridge. Dorsal fins separate or subcontinuous. 



Europe ; North America ; Japan. 



Synopsis of the Species. 



I. Supraoral lamina tricuspid ; intraoral lamina with 

 5 or cusps ; on each side 4 enlarged lateral 

 teeth, the Urst and last bicuspid, the middle ones 



tricuspid 1. tridentatus. 



II. Supraoral lamina bicuspid ; infraoral lamina with 6 to 9 cusps. 



A. On each side 4 enlarged lateral teeth, the first 



uni- or bicuspid, the otJiers bicuspid 2. sjjudiceus. 



B. On each side 3 enlarged bicuspid lateral teeth. 



Dorsal fins well separated 3. juponicus. 



].^rsal fins only separated by a notch 4, xoilderi. 



1. Entosphenus tridentatus. 



Petromyzm tridentatus, Richards. Faun. Bor.-Am. p. 293 (1836). 

 Ichthijomyzon trideyifufus, Giiiith. Cat. Fish. viii. p. 506 (1870). 

 Ichthyomyzon astori (Girard, 1858), Giinth. /. c. 



Entosphenus tridentatiis, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 

 1896, p. 12. 



Pacific Coast of North America, from Unalaska to Cali- 

 fornia, entering rivers. 



1-2. 570-590 mm. La Grande, Oregon. Prof. 0. H. Eigenmann. 



3. 480 mm. Walla Walla, Columbia R. Smithsonian Inst. 



2. Entosj)henus spadiceus. 



Lamjyetra spadicea, Bean, Proc. U.S. Nat. Mus. 1887, p. 374 ; Jord. & 

 Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 13. 



Rio Lerma, Mexico. 



1. 175 mm. Jacona, Michoachan. Mexico Mus, 



2-5. 110-155 mm. (larvae). „ ' -,, „ 



