FISHES 



27 



Subspecies of E. tridentatus 



E. t. tridentatus (Gairdner), Muscle segments between gills and 

 anus 68 to 74 : Columbia River and northwards. 



E. t. ciliatus (Ayres). Muscle segments between gills and anus 57 to 

 67: southern Oregon and southwards. 



E. appendix (DeKay) {E. wilderi Jordan & Evermann) (Fig. 12). 

 Length 200 mm.; color bluish black; enlarged lateral teeth 3 on a side, 

 all bicuspid; infraoral lamina with 8 to 11 cusps; supraoral lamina 

 bicuspid; muscle segments between gills and 

 anus 67 to 73; intestine of adult degenerate: 

 in streams from southern New England to 

 Maryland; westward to Wisconsin and Iowa; 

 northward into Canada; in eastern Asia. 



4. Lampetra Gray. Teeth very few, there 

 being usually 3 enlarged two-cusped laterals 

 on each side of the mouth; supraoral lamina 

 with 2 separated cusps, joined by a bridge: 

 3 American species. 



L.fiuviatilis (L). Length 350 mm.; dorsal 

 fins separated; 63 to 70 muscle segments be- 

 tween gills and anus; teeth strong and sharp; 



• _f' 1 1 • •,! ^ , , . Fig. 12. — Buccal funnel of 



mfraoral lamma with 6 to 9 cusps; anterior Entosphenus appendix {from 

 portion of buccal disc with many teeth : coasts Fishes of Illinois). 

 and streams of Europe, Asia and western North America from San 

 Francisco to Puget Sound. 



L. planeri (Block) {L. ciharia Girard). Length 200 mm.; color plum- 

 beous; dorsal fins separated only by a notch; teeth weak and blunt; 

 infraoral lamina with 6 to 9 cusps; anterior portion of buccal disc with 

 many teeth; intestine of adult degenerate; 57 to 66 muscle segments 

 between gills and anus : streams of Europe, Japan and western America 

 from Alaska to central California. 



L. lamottenii (LeSueur) {L. cepyptera Abbott) (Fig. 13). Length 

 120 mm.; teeth much reduced in number and size; infraoral lamina with 

 a crenulated crest and without distinct cusps; lateral teeth sometimes 

 uni cuspid and more or less obsolescent; anterior portion of buccal disc 

 with usually 4 teeth; 54 to 60 muscle segments between gills and anus: 

 in the Ohio and Potomac River basins. 



Subclass 2. Pisces. — The true fishes. Aquatic vertebrates with 

 gills which are attached to bony or cartilaginous gill-arches; with true 

 jaws; with median fins and usually two pairs of paired fins; in most cases 

 with scales; with paired nostrils: 3 divisions. 



