7& ANNUAL REPORT OF 



above list are treated as synonyms, the legitimacy of which 

 course was practically acknowledged by Newberry. For in- 

 stance, in the description of his so-called /. alatus, he tells us 

 that he "hesitated long before separating it from /. limaius, as it 

 is probable that the two will be found to run into each other, so 

 that they must be regarded as varieties of one species." Similarly 

 the differences between his Ischypterus elegans and /. lenticularis 

 were admitted to be so slight as to- be perhaps attributable to 

 age or sex; and under his description of /. modestus we read: 

 "The fishes most nearly allied to these are those which I have 

 included under the name of /. elegans, and it is perhaps not cer- 

 tain that they should be regarded as distinct." It will be seen, 

 therefore, that no violence is done to> the views of the original 

 author, to whom we owe much and valuable enlightenment, in 

 introducing a few slight modifications. 



Semionotus ovatus (W. C. Redfield). 

 (Plates 4-6.) 



1842 

 1847 



1850. 

 1888 



18 

 1903 



Palceoniscus ovatus, W. C. Redfield, Amer. Journ. Sci., vol. xli, p. 26. 

 (?) Tetragonolepis, Sir P. G. Egerton, Quart. Journ. Geol. Soc, vol. 



iii, p. 277. 

 Ischypterus ovatus, Sir P. G. Egerton, op. cit., vol. vi, p. 10. 

 Palceoniscus ovatus, J. H. Redfield, Monogr. U. S. Geol. Surv., vol. 



xiv, p. 27. 

 Ischypterus ovatus, Ibid, loc. cit. 

 Semionotus ovatus, G. F. Eaton, Amer. Journ. Sci., [4] vol. xv, p. 266. 



A large species, attaining a total length of about 23 cm. (9 in.), 

 with trunk very much deepened midway between the head and 

 dorsal fin. Scales large and thick, becoming gradually deepened 

 toward the middle of the flanks ; tail strong and considerably ex- 

 panded. Number of dorsal and anal fin-fulcra greater than in 

 any other species, each fin having sometimes as many as twenty 

 or more. Length of the longest fulcrum of dorsal fin nearly 

 equaling one-half that of the anterior margin of the fin. 



In the original description of S. ovatus, by W. C. Redfield, it 

 is stated that "it exceeds all the known American species in the 

 comparative width or roundness of its form, and is also remark- 

 able for the large size of its scales. It is of rare occurrence, and 



