lxii 
SYNOPSIS OF GENERA. 
EU CHONDE I A, Meek. 
Am. Jour. Sci., 3d ser., vol. vii, p. 445. 1874. 
[Type Pecten neglectns, Geinitz.] 
“ Mr. Meek states, in a letter to one of the editors, that he proposes to 
institute the genus Euchondria for Pecten negledus of Geinitz, on account of its 
peculiar hinge as illustrated by figure 7c, plate xxvi, in vol. v, of the Illinois 
Geological Report.” 
This genus as illustrated by Mr. Meek [ut cit.) has an unsymmetrical sub- 
rostral cartilage-pit, and the crenulations on the two sides are unequal. 
If these characters can be shown in other specimens and other species, it is 
probable that this genus will prove to be clearly distinct. At present it can 
include only a single species, E. negleda. 
The figures of this species given in the Palaeontology of Illinois, are intro¬ 
duced for comparison with Pernopeden and Crenipeden. 
Figs. 4, 5. Euchondria neglecta (Geinitz, sp.). A reproduction of figs. 7c and 
la, of plate xxvi, Geol. Surv. Illinois, vol. v. Fig. 4, a right valve, enlarged to 
two diameters. Fig. 5, an enlargement of the hinge. Coal measures. Illinois. 
hid 
