ABT,5 BIBLIOGEAPHY OF THE CONODONTS HOLMES 31 



PANDERODELLA SUBRECTA, new species 



Plate 10, fig. 15 



This specimen is a modification of Panderodella recta. The de- 

 flection of the bar is more noticeable. The denticles on the long side 

 of the bar are short, spear-shaped, and evenly spaced. Those on- 

 the deflected side are needlelike. 



Bolotype.—QdX, No. 11463, U.S.N.M. 



Genus POLYGNATHUS (Hinde) Bryant, 1921 



POLYGNATHUS GYRATILESTEATUS, new species 



Plate 11, figs, 1, 2 



Plate an irregular polygon with the tubercules united so as to 

 form parallel ridges extending in concentric lines from one side of 

 the median ridge to a place on the other side directly opposite the 

 point of origin. The median ridge, which is slightly flexed to the 

 right and to the left, is produced beyond the plate into a carina 

 bearing denticles. 



Cotypes.—C^i. No. 11454, U.S.N.M. 



POLYGNATHUS PERGYRATUS. new species 



Plate 11, fig. 3 



This species is very similar to Polygnathus gyratilineaius but the 

 lines are much closer together. The posterior end of the plate is 

 produced into a carina as usual in this type of species. 



Eolotype.—Cnt. No. 11455, U.S.N.M. 



POLYGNATHUS TRILOBATUS, new species 



Plate 11, fig. 4 



As its name indicates this is a distinctly three-lobed plate. The 

 anterior lobe is long and narrow, while the lateral lobes sweep in 

 broad lines from the anterior lobe to the carina. A low median 

 ridge rises in the middle of the anterior lobe becoming flattened 

 towards the top but gradually narrowing posteriorly until it is 

 produced beyond the plate into a broad carina, bearing denticles. 

 The tubercules of the basal portion are stronger and more concen- 

 trically arranged than in Polygnathus concentricus. The tubercules 

 of the anterior lobe extend from side to side across the top of the 

 median ridge. 



Eolotype.—C2it. No. 11456, U.S.N.M. . 



