304 Fishes of the Ohio 



Four plates between the anal and caudal fins, the two 

 middle in pairs. 



Pectoral fins large, falcate ; the dorsal, abdominal and anal 

 trapezoidal ; and the caudal lunate. 



Color. Head and body olive-brown above, white beneath. 

 Fins reddish. Younger specimens maculated on the body 

 and sides. 



Length 2 feet. 



Hah. Ohio river and Lake Erie. 



Observations. The description and drawing were made 

 from the same specimen, which was procured in the Cincinnati 

 market. The varieties occasioned by age, sex, locality and 

 other circumstances have occasioned me much perplexity, but 

 after five years close examination I feel a great degree of con- 

 fidence in throwing the whole group into one species, though 

 it presents a formidable list of synonyms. 



The color and form of the fish, and the number, size, and 

 position of the plates vary extremely in specimens of appa- 

 rently similar age, taken in the same locations. Two out of 

 five specimens lying in the Cincinnati market on the 23d of 

 December, 1840, presented characters different from any in- 

 cluded in the descriptions above referred to, and if variations 

 in the number and appearance of the shields, and in the forms 

 of the head and body constitute essential specific characters, 

 we must add several more new species to the list. These 

 characters are not however permanent, and therefore are not 

 to be relied upon. If the maculosus of Le Sueur be not the 

 young of the others, their young have never been discovered. 

 The extreme old, shed entirely their shields, the surface of the 

 body becomes naked and they lose some of their essential 

 generic characters. It was a drawing and description of an 

 individual in this condition, that I formerly communicated to 

 the Boston Society of Natural History under the name of A. 

 nudus. I have since seen several individuals of this character 

 taken in Lake Erie and in the Ohio river. 



