346 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Take the most salient characters of the genus Euchalarodus — the mov- 

 able teeth and scarcely perforate anterior nasal tubes — the same condi- 

 tions may be observed in Pleuronectes glaber and P. platcssa. Euchala- 

 rodus Putnami, in fact, is the male of Pleuronectes glaber, and differs from 

 it only in having more of its scales ciliated. The young are like the 

 adult male in this respect. Had all the examples of Pleuronectes platcssa 

 exhibited movable teeth, it would have led to the belief that Euchalarodus 

 after all might be applied to the species of Pleuronectes with movable 

 teeth, but one of them has the teeth firmly fixed, another has some in 

 the upper jaw movable, and a third has all the teeth reclining and freely 

 movable. The explanation of this condition is yet to be sought. 

 The materials used in this examination are as follows: 



5368. Types (2) of Euchalarodus Putnami. Salein, Mass. Putnam. (Teeth of larger 



movable. ) 



20910. Pleuronectes glabcr, $ . Portland, Me. Tarleton II. Bean. (Teeth movable.) 



20920. 







$ and $ . Salem, Mass. 



C.F 



. Putnam. 



(Teeth movable.) 



20954. 







(7 young*). 



Bucksport, Me. 



C. G. Atkins. 



(Teeth lixed.) 



14657. 







(half-grown). 



Portland, Me. 



Summer, 1872. 



(Teeth fixed.) 



14659. 







yy 



yy 



yy 



yy 



yy 





y y 



yy 



yy 



14662. 





yy 



yy 



yy 



yy 



yy 



yy 







yy 



yy 



14666. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



11667. 



ft 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14669. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 





yy 



14673. 



» 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14677. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14678. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14679. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14681. 



)> 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yt 



14682. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14683. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14684. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14685. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14658. 



yy 



yy 



(adult 9). 



yy 



yy 



yy 





yy 



yy 



yy 



14661. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14663. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14664. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14665. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14671. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



14672. 



yy 



yy 



yy 



yy 



yy 



yy 



yy 





yy 



yy 



yy 



Ml 74. 



>y 



yy 



>» 



yy 



yy 



yy 



yy 







yy 



yy 



20873. 



yy 



yy 



(1<? and 2 9). 



yy 



yy 



Dec, 



15, 



1877. 



(Teeth njov- 

























able.) 



20954. 



yy 



yy 



.(3 spent 9 ). 



Bucksport, Me. Mar. 



4, 



1878. 



( Teeth transi- 

























tional.) 



It will be seen that the teeth of the adult male and female are freely 

 movable only during the breeding season, and that those of the young 

 arc fixed. 



10029. Pleuronectes platcssa. "Kiel. Dr. Miibius. (Teeth fixed.) 

 10061. „ „ Christiania, Norway. R. Collett. (Teeth movable.) 



21175. „ „ France. Mus. d'Hist. Nat. Paris. (Some teeth of upper 



jaw movable.) 



*Tho longest of these is 140 mm in length. All have rough scales. 



