266 Storefs Synopsis of the Fishes of North America. 



Length, (?). 



Petromyzon Lamottenii, Lesueuk, Hist. N. A. Fishes, ined., plate. 

 " " " Dekay's Report, p. 3S2 



4. Petromyzon tridentatus, Gairdner. 



Back and sides bluish gray, with irregularly scattered yellowish patches ; belly yellowish 

 white. Three conspicuous and contiguous teeth on the upper side of the maxillary ring. 

 Dorsals distinct. 



Length, 21 inches, G lines. 



Columbia River, Richardson. 



Called " Squaqual," by the Indians on the banks of the Wallamet. 



Petromyzon tridentatus, Tridentale Lamprey, Gairdner, Kich., Fauna Boreal. Americ, SIX. p. 293. 

 " " Dekay's Report, p. 382. 



5. Petromyzon argenteus, Kirtland. 



Body cylindrical, compressed towards the back. Back ash-gray ; sides and beneath 

 silvery-gray, maculated with irregular rows of black dots. A black dot over each branchial 

 opening. Dorsals continuous. 



Length, 11 inches. 



Big Miami River, Ohio, Kirtland. 



Petromyzon argenteus, Kirtland's Report, pp. 170, 107. 



" " Lamprey, Kirtland, Bost. Journ. Nat. Hist., ill. p. 342, pi. 4, fig. 3. 



" lt Dekay's Report, p. 382. 



6. Petromyzon appendix, Dekay. 



Dorsals continuous, yellow. Anal fin with a thread-like appendix on its anterior portion. 



Length, 4 to G inches. 



Rhode Island, New York, Dekay. 



Petromyzon appendix, Small Lamprey, Dekay's Report, p 331, pi. 64, fig. 211. 



7. Petromyzon fluvialis, Lin. 



Richardson, in his " Fauna Boreali Americana," says, — "A Lamprey, having teeth like 

 P. fluvialis, was found in Great Slave Lake, adhering to an Inconnu (Salmo Mackenzii). It 

 was very like Bloch's figure of the P. argenteus, which Cuvier thinks is not different from 

 fluvialis." 



GENUS II. AMMOCCETES, Dumeril. 



Form of the body, the branchial apertures, and fins, like those of the Lam- 

 preys ; upper lip semicircular, with a straight, transverse under lip ; mouth 

 without teeth, but furnished with numerous short membranous cirrhi. 



