14 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 08 



tlioii<j:h unequal sized lateral denticles of which there are seven to 

 nine and the thickness of the posterior half of the bar. 



Occurrence. — Devonian (Khinestreet) : Shaleton, N. Y. 



Cotyyes.—Q^i. No. 11247, U.S.N.M. 



LIGONODINA MAGNIDENS, new species 



Plate 2, figs. 5, 6 



This species founded upon two teeth showing opposite sides is 

 well characterized by the four middle denticles which are very 

 large almost reaching the size of the main cusp. A pair of much 

 smaller although still relatively long denticles lies on both sides 

 of the larger set. 



OccMrrence. — Devonian (Rhinestreet) : Shaleton, N. Y. 



Cotyj)es.—Q2X. No. 11248, U.S.N.M. 



LIGONODINA FALCIFORMIS, new species 



Plate 2, figs. 11-13 



Like L. pectinata but the denticles are fewer and more inclined 

 backward to the axis of the bar, the last ones being about at an 

 angle of 50 degrees and most of them distinctly larger. The main 

 cusp also is more curved. The furrow along the anterior edge of the 

 main cusp is narrower and depressed beneath the level of the pos- 

 terior half. In other species the opposite is the case. 



OceutTevce. — Devonian (Rhinestreet) : Shaleton, N. Y. 



Coty pes.— Cut No. 11249, U.S.N.M.. 



LIGONODINA HINDEI. new species 



Plate 2, figs. 14-16 



Characterized by the much greater incurving of both the main cusp 

 with its downward extension and the denticles and the relatively 

 even length and strength of the lateral denticles of which there are 

 seven. The average thickness of the lateral denticles is greater 

 than in any of the other species here recognized. The first five are 

 of more uniform length and size than in any other species. 



Occurrence. — Devonian (Rhinestreet) : Shaleton, N. Y. 



Cotypes.— Cat. No. 11250, U.S.N.M. 



LIGONODINA HIBBARDI, new species 



Plate 2, figs. 7, 8 



Somewhat like L. hindei but with a shorter and more delicate 

 bar, fewer (five or six) and more slender denticles and the peculiar 

 straightness of the backwardly directed main cusp. The latter 



