m. 



COTTOIDS OF NORTH AMERICA. 



69 



DIAGNOSIS 



GENERA AND SPECIES 



CONTAINED IN THIS 



MONOGRAPH. 



COTTUS, Artedi.— Upper surfoce of Lead, 

 smooth. One small spine on the side of the head ; 

 sometimes a second still smaller below, and occa- 

 sionally a third of the size of the second. First dor- 

 sal fin lower than the second. Palatine teeth none, 

 or rudimentary. Cleft of mouth not extending be- 

 yond the orbits. Six branchiostegal rays. 



I. Rays of ventral fins, five in number. 



CottUS COg^natllS, Rich. — Body fusiform. 

 Origin of anal fin opposite to sixth ray of second 

 dorsal. Pectorals equalling the head in length. 

 Anus situated nearer the snout than the base of 

 caudal fin. 



Cottus Richardsonii, Agass. — Body fu- 

 siform. Origin of anal fin opposite to third ray of 

 second dorsal. Pectoral fins shorter than the head. 

 Anus situated midway between the snout and tip of 

 caudal fin. Insertion of ventrals in advance of the 

 anterior dorsal, and near the lower edge of pectorals. 



CottUS 'Wilsonii, Grd. — Body fusiform. 

 Upper rays of pectoral fins, branched; their tip 

 reaching the anterior margin of second dorsal fin. 

 Insertion of ventral fins under the middle of pecto- 

 rals, and in advance of the anterior dorsal. 



CottuS Bairdii, Grd. — Body fasiform. First 

 dorsal fin very low. Tip of pectorals extending be- 



DIAGNOSIS 

 GENERUM ET SPECIERUM 



IN HOC 



MONOGRAPHO 



DESCRIPTOBUM. 



COTTUS, Artedi.— Capitis superficie Icvi ; 

 spina parva ex capitis latere utroque, interdum al- 

 tera aliquanto minore, infra posita, et nonnunquam 

 tertia magnitudine sequali secundae. Pinna dor-sali 

 prima breviore secundS,. Dentibus palatinis nullis, 

 vel corum rudimentis tantum. Oris fissura ultra 

 orbitas non porrecta. Radiis branchiostegis sex. 



I. Pinnarum ventralium radiis, quinque. 



Cottus COgnatus, Rich. — Corpore fusi- 

 forme. Origine pinna3 analis ex adverse sexto 

 secundae pinnaj dorsalis radio. Pinnis ventralibus 

 capite longitudine asqualibus. Ano propius rostrum 

 quam pinnae caudalis basim posito. 



CottllS Richardsonii, Agass. — Corpore 

 fusiforme. Origine pinnae analis ex adverso tertio 

 secundae pinnae dorsalis radio. Pinnis pectoralibus 

 capite brevioribus. Ano medio inter rostrum et 

 pinnae caudalis extremitatem. Pinnis ventralibus 

 ante dorsalem anteriorem et prope inferiorem pecto- 

 ralium marginem, insertis. 



CotttlS 'Wilsonii, Grd. — Corpore fusiforme. 

 Superioribus pinnarum pectoralium radiis divisis, 

 eorumque extremitate ad anteriorem pinnae dorsalis 

 secundse marginem porrecta. Pinnis ventralibus 

 sub pectoralium medio et ante dorsalem anteriorem, 

 insertis. 



Cottus Bairdii, Grd. — Corpore fusiforme. 

 Pinna dorsali prima, admodum brevi. Extremitati- 



