EASTMAN: FISHES FROM UPPER EOCENE OF MONTE BOLCA. 331 



every respect the prototype of the PleuronectidsE before they had assumed the 

 asymmetry which characterizes them as a group." By the author just named this 

 supposed ancestral flat-fish is placed in close association with the Zeidae, from which 

 family it differs, however, in the smaller number of vertebrse, and in having the 

 dorsal and anal spines more reduced, adnate, and continuous with the series of soft 

 rays. A copy of Boulenger's restoration of this species is given in figure 3. It 



Fig. 3. Amphislium paradoxmn Agassiz. Upper Eocene, Monte Bolca, Italy. Skeleton as 

 restored by Boulenger, about one-half the natural size. (C/. Mem. Carnegie Museum, Vol. IV, p. 383). 



is based upon two nearly complete specimens preserved in the British Museum of 

 Natural History and these two specimens afterwards furnished Dr. Regan the 

 basis for the following statement: 



" I much more readily subscribe to Boulenger's view that the Upper Eocene 

 Amphistium is allied to the symmetrical ancestor of the flat-fishes, for in my opinion 

 this fish is a Percoid, which should probably be placed in the family Scorpididse 

 near the existing Psettus, or may perhaps be related to Platax. Thanks to the 

 courtesy of Dr. A. Smith Woodward, I have been able to examine the two examples 

 of Amphistium paradoxum in the British Museum. The caudal fin has seventeen 

 principal rays above and below (Agassiz gives the formula for this fin: 6. I. 8; 

 7. I. 2) ; the pelvic fin, preserved only in the Monte Bolca specimen, is formed of a 

 spine, and, in my opinion, five soft rays, for I cannot see a greater number inserted 

 on the pelvic bone which lies uppermost, the outlines of which are fairly distinct. 



" Boulenger's restoration shows several features of Psettodes or Zeus which 

 I am unable to see in the fossils; thus he shows the lower jaw nearly as long as the 

 head and the pre-operculum vertical and scarcely curved, whereas the lower jaw 

 appears to be only a little more than half the length of the head, and the pre-oper- 

 culum to have a distinct lower limb; also the origin of the anal fin is not so far 



