LAMPETRA — BROOK LAMPREYS 



II 



Genus LAMPETRA Gray 



(BROOK LAMPREYS) 



Supraoral plate crescent-shaped, with a large bluntish cusp at each 

 end, separated by a wide space, there being rarely a very small median 

 cusp; lingual teeth small, with dentate edges, the median denticle en- 

 larged; dorsal fin with a sharp notch or entirely divided. Small lampreys 

 of the brooks of Europe and North America. 



Fig. 10 



Oral disk of Brook Lamprey (Lampetra 

 wilder: J, & E.) 



LAMPETRA WILDERI Jordan & Evermann 



(bro<>k lamprey; small black lamprey) 



Rafinesque, '20, [chth. Oh., 84 iPetromyzon nigrum; name preoccupied) ; Jordan 



& Evermann, '96, B. U. S. X. M., 47. I, 13. 

 G., VIII, 504 iPetromyzon branchialisi ; J. & G., 9 (Ammocoetes niger); M. V., 10 



(A. branchialisi; N\, ; 2 (P. niger I , J., 70 (A. niger); P., 86 (A. niger); L., 7. 



Length 6 to 10 inches; depth 13 to 16 in length; width of body L.3 

 to 1.4 in its depth; distance from last gill-opening to front of dorsal 3.4 

 to 3.5 in length; last gill-opening to vent 1.9 to 2; muscular impressions 

 70 73. Color bluish Marl, above, silvery below. Head (to first "ill 

 opening) 7.9 to 8.7 inlength; diameter of expanded buccal disk less 

 than \ bead; fimbriae consisting of small and closely set tubercles, 

 nol arranged in definite rows, and dense, i mi lower lip; no flexible 

 lip inside fimbriae; eve 6 to 7 in head; supraoral lamina with a large 

 triangular cusp at each end. separated by an interval nearly twice the 

 width of base ol a ingle cusp; infraorals 6 or 7, a siiv.de cusp at eai h 



