152 



carrying out the objects of his mission. He exhibited a 

 sketch of the feather of the ruddy duck, its structure 

 being very peculiar, consisting of two feathers, in fact ; 

 the first an odd or deciduous feather, which was pushed 

 up from the flesh by the true feather, in a similar manner 

 to the first teeth of the child, which are pushed out by the 

 second. He said that this was a contribution to science 

 by Dr. Elliot Coues, U. S. A., and that it would be pub- 

 lished with a cut in the American Naturalist. 



Mr. Putnam presented the following paper by Dr. 

 CARPENTER : 



ON THE GENERIC AFFINITIES OF THE NEW ENGLAND CHITONS. 



BY PHILIP P. CARPENTER, OF MONTREAL. 



IT has been common with conchologists, even of the "advanced" 

 school, to call every mollusk with eight valves a Chiton, except the 

 vermiform species, which Lamarck separated as ChUonellus. The con- 

 sequence has been that very little is known of most Chitonidae, except 

 the external characters ; the differentiation shown in the soft parts, 

 and even in the shelly valves, having been overlooked. 



We have been fortunate, during the explorations of the United 

 States Fish Commission, in observing four species alive ; another was 

 taken alive at Eastport last year ; a sixth has been captured on the 

 southern coast. These are all as yet known to inhabit the American 

 Atlantic seas, from Labrador to Florida. A seventh, called Chiton 

 cinereus, is said to have been taken alive by Dr. Pickering, and to be 

 in the collection of the Philadelphia Academy of Natural Sciences ; 

 but it may prove to belong to one of the other species, or to be a 

 ballast specimen. 



The six authentic species present well-marked characters, ranging 

 under five genera. 



It may be premised that the Lamarckian genus Chiton was first 

 divided by the Rev. L. Guilding, according to the external characters 

 of the West Indian species. About the same time, the Rev. T. Lowe 

 published the peculiarities in the insertion plates of the British spe- 

 cies. Both papers appeared in the " Zoological Journal." Dr. Gray, 

 however, was the first to present, in the Proc. Zool. Soc., a full de- 

 scription of the forms of Chitonidse, accurately arranged under 

 genera and sections, partly according to the external, but prin- 



