ART. 12 CLASSIFICATION OF CONODONTS — ULEICH AND BASSLER 4? 



arrangement of the series of surface nodes. The crest is apparently 

 without nodes. 



Occwrrence. — Mississippian (Hardin sandstone) : Mount Pleasant. 

 Tenn. 



Cotyyes.—Qvii. No. 10998, U.S.N.M. 



POLYGNATHUS SUBLATUS, new species 



Plate 8, fig. 2 



Quite similar to P. pennatulus except that the whole form is 

 broader, the lateral area flatter, the mid-rib does not reach the 

 anterior extremity, and the rows of tubercles have a tendency to 

 radial arrangement. 



Occwrrence. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



H olotype. —C2ii. No. 11009, U.S.N.M. 



POLYGNATHUS? ACAULIS, new species 



Plate 8, figs. 4, 5 



Our illustrations of the upper and lower surfaces of two plates 

 show the characteristic triangular outline and absence of stalklike 

 projection of the median crest. Hinde gives poor figures of two 

 specimens named P. truneatus^ wdiich must be related to this species. 

 These are also of triangular form and lack the stalk. Even the 

 median crest is not represented on the larger of the two which 

 moreover comes from a very different geological horizon. Until 

 specimens of Hinde's species are found, fuller comparisons are not 

 possible. The present species differs from all others and must be 

 considered a doubtful form of the genus. 



Occurrence. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



C oty pes.— C2it. No. 11003, U.S.N.M. 



POLYGNATHUS CONCENTEICUS, new species 

 Plate 8, fig.s. G, 7 



We figure the upper and lower surfaces of two plates, the former 

 showing the highly ornamental concentric arrangement of tlie sur- 

 face tubercles reminding of P. con-fiuens but the specimens are larger 

 and the outline is less regularly lanceolate. 



Occurrence. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



Gotypes.—Qai. No. 11002, U.S.N.M. 



