80 MONOGRAPH OF TIIE FRESH WATER COTTOIDS, ETC. III. 



FAGK 



4. Species with three soft rays to the ventrals . 



VII. Cottus gracilis . . 1;i 



VIII. C.ittus \isi-osus ... 51 



IX. Coitus l-'ranklinii .... 



X. Cottus gobioides ...... "'"' 



XI. Cottus boleoides ... 5G 



MI. Cottus formosus 



MIL Cottus Fubricii . ''' 



CHA1TER IV. 



ON TIIE OENU8 COTTOP8I8, Girard. 

 Cottopsis aspcr 



CHAPTER V. 



ON TIIE UENUS TRIGLOl'SIS, (iirard. 



Triglopsis Tliouipsouii . ''' 



Note 



Diagnosis of the genera and species 



Bibliography ... 



Explanation of the plates 



Alphabetic register of systematic names alluded to iu this monograph 



Contents ..... 7'.' 



PUBLISHED BY T1IK SMITHSONIAN INSTITUTION. 

 WA8H1 NOTON CITY, 



DECEMBEK, 1851. 



