Cope.] l^S [Jan. 5, 



EXPLANATION OF PLATES. 

 Figures all natural size uuless otherwise stated. 



Plate IV. 

 Fig. 1. Xiphorhamphus hrachycephalus Cope ; a. head from above. 



Plate V. 



Fig. 2. AsiplionicMhys stenopterus Cope. 



3. Chorimycterus tenuis Cope. 



4. Diupoma spectiUferum Cope. 



5. Tetragonopterus pUodus Cope. 



Plate VI. 



Fig. 6. Tetragonopteri/s jacuJdensis Cope. 



7. Tetragonopterus laiiceps Cope. 



8. Tetragonopterus eigenmanniorum Cope. 



9. Chirodon monodon Cope. 



Plate VIL 



Fig. 10. Rhamdella straminea Cope. 



11. Hisonotus leptochilus Cope. a. Head from above f natural size ; 



b. Head from below. 



12. Hisonotus Iwdior Cope. a. Head from above | natural size ; 



b. Head from below. 



13. Otociiiclus flexilis Cope. a. Head from above | natural size ; 



b. Head from below. 



Plate VIIL 



Fig. 14. Plecostomus aspilogasier Cope, | natural size. a. head from 

 below X |. 

 15. Loricaria cadem Hensel, from side. a. From above ; b. From 

 below I natural size. 



Plate IX. 



Fig. 16. Otocindm fimbriatus Cope. a. Head from above x 2 ; J. 

 Head from below x 3. 



17. Qeophagus camurus Cope.. 



18. Qeophagus brachyurus Cope. 



