42 PROCEEDINGS OF THE NATIONAL MUSEUM vou 68 



SYNPRIONIODINA, new genus 



Like Palmatodella except that the downtiirned anterior part is 

 much smaller, bar thicker, denticles not turning forward so sharply 

 and the main cusp proportionately very large. Probably more 

 closely allied to Euprioniodiim the essential difference being the 

 almost complete lateral fusion of the denticles. 



GeTwtype. — Synpnoniodi7ui alternata., new species. 



Range. — Upper Devonian and Early Mississippian. 



SYNPRIONIODINA ALTERNATA. new species 

 Text fig. 22 (p. 10) 



Main cusp large, straight, rounded and directed as much forward 

 as ujjward. Denticles on bar consisting of two alternating subequal 

 sets, not strongly inclined, laterally fused, numerous, rather short 

 slender, those on the downturned snbtiiangular anterior part directed 

 forward, about seven in number, all of same width but decreasing 

 regularly in length from above downward. 



Occurrence. — Mississippian (Chattanooga shale) : 13 miles east of 

 nortli of Huntsville, Ala. 



Holotype.— Cat. No. 11308, U.S.N.M. 



Genus LONCHODUS Pander, 1856 

 Text fig. 10 (p. 10) 



The genus Lonchodus originally described as Centrodus by Pan- 

 der* but changed by him to Lonchodus on account of priority is 

 undoubtedly based upon broken incomplete remains of teeth which 

 as our illustrations show might belong to any one of several distinct 

 genera. As it is probable that the true characters of the genus now 

 caii not be accurately determined the only use we can suggest for 

 the name is to continue employing it for species based upon similar 

 imperfect and generically indeterminable material. 



Genotype. — Lonchodus {Centrodus) simplex Pander, 185G. 



Genus CORNURAMIA Smith, 1907 

 Text figs. 1, 2 (p. 10) 



" In this genus there is a double-pointed, hornlike beam " (Smith, 

 1907). 



No American species of this type is known. 



Genotypes. — Cot^uramia monodonta Smith, 1907. Ordovician of 

 Scotland. 



