32 PROCEEDINGS OF THE NATIONAL MUSEUM vol.68 



one end of equal size and three or four of larger though irregular 

 sizes in middle part of tooth and two relatively small ones on the 

 other e]id. It is difficult to pick out the main cusp. 



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



Cotypes.—C^t. No. 11278, U.S.N.M. 



LONCHODINA ARCUATA, new species 



Plate 5, fig. 15 



Bar strongly arcuate, curved so that the extremities are at ap- 

 proximately right angles, bearing an anterior series of denticles 

 all curving inward, the others beginning with the main cusp, 

 straight and excepting the one nearest the main cusp diminishing 

 outwardly in size. These characteristics especially the arcuate bar, 

 readily distinguish this species. 



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



Holotype.—C-At. No. 11279. U.S.N.M. 



LONCHODINA BILATERALIS, new species 



Plate 5, fig. 18 



Bar with subequally down-curved extremities, crowned by 11 

 straight diverging denticles of which 2 are very large and nearly 

 equal in size, 3 outwardly diminishing denticles on one side, 2 

 or 3 between the large pair and 4 much smaller ones on the other 

 end. Except the last, which are also slender, all the other teeth are 

 thick, joined below and taper rapidly toward their extremities. 



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



nolotype.—C2it. No. 11280, U.S.N.M. 



LONCHODINA PERLONGA, new species 

 Plate 5, figs. 6, 7 



Similar to the genotype L. typicalis, but all the denticles are more 

 slender, relatively longer, with one or two more on either side of the 

 median cusp. All the denticles are slightly curved and divergent 

 toward their tips. Moreover, they are closer together, although 

 remaining separate to the bar. 



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



Holotype.— Cat. No. 11280, U.S.N.M. 



LONCHODINA SUBANGULATA. new species 



Plate 5, fig. 3 



Similar to L. perlonga except that the bar is angulated, the den- 

 ticles are closer together, and the main cusp, though little curved. 



