30 PROCEEDINGS OF THE NATIONAL. MUSEUM VOi^ 72: 



Genus SYNPRIONIODINA Ulrich and Bassler, 1926 



SYNPRIONIODINA ALTERNATA Ulrich and Bassler, 1926 



Plate 10, figs. 11, 12 



1926. Synpriomodma alternata Ulkich and Bassler, Proc. U. S. Nat. Mus^. 

 vol. 68, p. 42, text, fig. 22. 



Both of these specimens exhibit the interior sides of two opposite 

 plates. The long, stout cusp, tapering to a very blunt point, divides 

 the bar into two unequal parts. The denticles are merely indicated 

 on the short side of the sharply arched bar. The long side bears a 

 number of long, needlelike denticles. In some places the relatively 

 wide spaces between the denticles are filled with very fine denticles.. 

 In Figure 11 the denticles are much longer than those in Figure 12. 



Holotype and plesiotype. — Cat. No. 11308, U.S.N.M. 



SYNPRIONIODINA PLANA, new species 



Plate 10, fig. 13 



The bar is very broad, flat, and strongly arched. A median ridge 

 divides the bar into two parts. The cusp is flat, very wide, and 

 tapers a little toward a rather wide, blunt point. It is about twice 

 the length of the other denticles, which are similar in shape. The 

 spaces become wider as both ends of the bar are approached. All of 

 the denticles are set at right angles to the bar, which is very long on 

 the steeper side of the arch. This specimen, as well as several others 

 the bars of which are divided by the median ridge, gives one the 

 impression of being one of a series, set in a jaw, as the shark's 

 teeth are. 



Holotype.— Q2.t, No. 11461, U.S.N.M. 



Family POLYGNATHIDAE Ulrich and Bassler, 1926 

 Genus PANDERODELLA Ulrich and Bassler, 1926 



PANDERODELLA RECTA, new species 



Plate 10, fig. 14 



Our figure shows the convex side of the plate or tooth, the bar of 

 which is very flat and broad. The cusp, which is scarcely different 

 from the other short, blunt pointed denticles, is moderately produced 

 as a flange below the bar. These denticles are all widely separated. 

 The terminal tooth of the long side helps to form a convex end 

 to the bar. 



Holotype.— C&i. No. 11452, U.S.N.M. 



