Eastman: Triassic Fishes. 141 



higher group arc not to be sought among the si)erialized types of the 

 former but among those with the most generalized secondary char- 

 acters. "- 



There are some matters of historical interest relating to early 

 studies of the Catopteridse and Seminotidae in this country, which may 

 be introduced at this point, before proceeding to a discussion of newly 

 observed structural details. The pioneer students of the Triassic 

 fish-fauna of America were William C. and John H. Redfield, father 

 and son, who contributed in all ten publications during the interval 

 between 1837 and 1857. 



In the first paper published by the junior author, to which reference 

 has already been made, the type species of Catoptenis is described, 

 and provisional identifications are made of three Semionotid species. 

 The latter were not at that time recognized as belonging to the genus 

 Semionotus, nor in fact did either of the Redfields perceive that the 

 half-dozen species of " Palaeonisci" with which they were acquainted, 

 and afterwards included in Ischypteriis Egerton, were actually con- 

 generic with the earlier described Semionotus Agassiz. 



Next in chronological order after the younger Redfield's paper of 

 1837 appeared an article by W. C. Redfield, entitled "Short Notices 

 of American Fossil F"ishes." This was published in the American 

 Journal of Science for October, 1 841, and included brief diagnoses of 

 the known species of " Palaioniscus " {i. e. Semionotus) and Catop- 

 terus. During the following year Sir Charles Lyell visited this 

 country, and in company with Professor Benjamin Silliman, Jr., as 

 he tells us, made at Durham, Connecticut, a fine collection of the 

 remains of fishes from the Trias of the Connecticut Valley. These 

 were examined in 1844 by Sir Philip Grey Egerton, and subsequently 

 by Professor Louis Agassiz, whose notes in regard to them and other re- 

 mains of American fishes, are quoted by Lyell in a paper published by 

 him in 1847.^ 



It is in this communication by Sir Charles Lyell that the new generic 

 terms Dictyopyge and Ischypterus were first proposed by Sir Philip 

 Egerton, the former to include the species already described by W. C. 

 Redfield under the designation of Catopterus macrurus, and the latter 



2 Woodward, A. S., Catalogue of the Fossil Fishes in the British Museum, Part 

 III, Introduction, p. vii. London, 1895. 



3 Lyell, C, "On the Structure and Probable Age of the Coal-field of the James 

 River, near Richmond, Virginia," Qiiar. Joiirn. Geol. Soc, 1847, Vol. Ill, pp. 275- 

 278. 



