Nui'lh American Speck's of Petromyzontidce. 2 ( .)1 



in A branchialis ; insertion of dorsal a little behind middle of body: 

 63 muscular depressions between last gill-opening and vent ; color 

 plumbeous above, sides and below silvery. - - Cibarius, 7. 

 cc. Dorsal fin continuous, the two parts of the fin separated not quite to 

 base bj- a sharp notch ; insertion of dorsal fin a little before middle 

 of body ; both dorsals high, the first If in height of second ; teeth 

 very feeble ; intraoral plate with from 5 to 9 feeble, bluntish, sub- 

 equal cusps, about 3 bicuspid teeth on each side of buccal disk ; teeth 

 on upper part of disk simple ; supraoral lamina rarely with a median 

 cusp ; head about as long as thorax, 8^ in total length ; 67 muscu- 

 lar impressions between last gill-opening and vent ; color bluish- 

 black, silvery below. ----- Branchialis, 8. 



5.-AMMOC(ETES TRIDENTATUS. 



?Pelromyzonmarinus camtschaticus Pallas, Zoogr. Rosso- Asiatica, III, 1811, 

 67 (Kamtschatka). 



Petromyzon trideniatus Gairdner Mss. , Richardson, Fauna Boreali-Americana, 

 1836, 293 (Columbia River). DeKay, New York Fauna, Fishes, 1842, 

 382 (copied). Storer, Synopsis Fish. N. A., 1846, 266 (copied). 

 Gray, "Proc. Zool. Soc, London, 1851, 240, pi. 19." Gray, Cat. 

 Chondr. Fish. Brit. Mus., 1851, 144. Girard, U. S. Pac. R. R. Surv.. 

 377, 1858 (Fort Reading, Cal.). 



Entosphenus trideniatus Gill, Proc. Ac. Nat. Sci. Phila., 1862. 331 (name 

 only). Jordan & Gilbert, Proc. U. S. Nat, Mus., 1880, 458, and 1881, 

 30 (Columbia R. at Astoria and Monterey Bay at Santa Cruz). Jor- 

 dan & Gilbert, Syn. Fish. N. A,, 1883, 868. 



Ichihyomyzon tridentatus Giinther, Cat. Fish. Brit. Mus., VIII, 1870, 506 

 (copied). 



Lampetra tridentata Jordan & Gilbert, Synopsis Fish. N. A., 1883, 7. Bean, 

 Proc. U. S. Nat. Mus., 1882, 89, 93 (Walla Walla River, and Garrison 

 Creek Washington Ter.). 



Ammoccetes trideniatus Jordan, Cat. Fish. N. A., 1885, 3. 



Petromyzon ciliaius Ayres. Proc. Cal. Ac. Sci. 1855, 43 (San Francisco). Gi- 

 rard, U. S. Pac. R. R. Surv., 1858. 378 (San Francisco). 



Eniosphemis ciludus Gill, Proc. Ac. Nat. Sci. Phila., 1862, 331 (name only). 



Petromyzon lividus Girard, U. S. Pac. R. R. Surv., 1858, 378 (Wahmah- 

 math R.). 



Petromyzon astori Girard, U. S. Pac. R, R. Surv., 1858, 380 (Columbia R. at 

 Astoria). 



Entosphenus astori Gill, Proc. Ac. Nat. Sci. Phila., 1862, 331 (name only). 



Ichihyomyzon astori Giinther, Cat. Fish... VIII, 1870, 307 (copied). 



Lampetra astori Jordan & Gilbert, Syn. Fish. N. A., 1883, 8 (copied). 



Entosphenus epihexodon Gill, Proc. Ac. Nat. Sci. Phila., 1862, 331 (based on 

 Petromyzon tridentatus Girard, erroneously supposed to be distinct from 

 P. tridentatus Gairdner). 



Lampetra epihexodon Jordan & Gilbert, Syn. Fish. N. A., 1882, 8 (copied). 



