THE SESSILE BARNACLES. 



11 



NOTES ON FOSSIL BARNACLES. 



The limits of this work do not allow of any discussion of the Ameri- 

 can tertiary barnacles, except in the case of Balanus concavus, which 

 also occurs as a recent species. On account of the importance of the 

 subject, some notes are given on supposed Palaeozoic Balanidne. 



Protobalanus hamiltonensis Whitfield 1 from the Marcellus shale, 

 Hamilton group of the Devonian of New York, is described as having 

 12 wall plates and perhaps 7 opercular valves. It has a certain 

 superficial resemblance to Balanus, but is morphologically inconsistent 

 with the Balanornorph barnacles. I doubt very much whether Proto- 

 balanus is a cirripede, but if so it must represent a group unrelated 

 to any known Mesozoic or later form. 



> Bull. Amer. Mus. Nat. Hist., vol. 2, 18S9, p. 67, pi. 13, fig. 22. 



