LIST OF FISH. 137 



.Synopsis of Genera. 

 a. Petroniyzouina. — Teeth distinct ; eyes visible. 



1. Petromyzon. — Upper inner teeth two, conical, close together ; 

 lower single, crescent-shaped ; labial teeth numerous, conical ; lin- 

 gual teeth two, pinnate, t. 1, f. 1. 



2. Lampetra. — Upper and lower teeth transverse, crescent- 

 shaped ; labial teeth in two submarginal rows ; inner lateral teeth 

 larger, two or three-lobed, lingual teeth pectinate, t. 1, f. 2. 



3. Geotria. — Upper and lower teeth transverse, crescent-shaped ; 

 upper lobed; labial teeth numerous, distant, acute, innermost 

 largest; lingual teeth elongate, conical, arched, t. 1, f. 3. 



4. Velasia. — Upper and lower teeth transverse, crescent-shaped ' 

 upper two-lobed ; labial teeth numerous, crowded, truncate ; inner- 

 most largest ; lingual teeth elongate, arched. 



5. Caragola. — Upper internal teeth two, far apart, three-lobed * 

 lower crescent-shaped, nine-lobed ; labial teeth transverse, band-like 1 

 four tubercles ; lingual teeth flattened, t. 1, f. 5. 



6. Mordacia. — Upper inner teeth two ; lateral three-lobed ; 

 lower nine, conical, in an arched series ; labial teeth conical, in a 

 single sub-marginal series ; lingual teeth elongate, conical, arched, 

 t. l,f. 6. 



b. Ammoccetina. — Teeth none ; eyes hidden. 



7. Ammoccetes. 



a. Petromyzonina. — Teeth distinct. 



1. PETROMYZON. 



Upper inner teeth two, triangular, close together. Lower inner 

 tooth single, large, crescent-shaped, many-toothed. Labial teeth 

 conical, acute, numerous, in diverging, arched series ; the inner one 

 largest, and gradually becoming smaller near the edge. Tongue 

 with two compressed, pectinated teeth above, and a broad, lunate, 

 dentated tooth beneath, which is strongly bent up between the up- 

 per teeth in the centre, t. 1, f. 1. 



Yarr. Brit. Fish. fig. p. 603 (not good). De Kay, Zool. New York. 

 t. 56, 216. (bad). 



n3 



