AKT. 12 CLASSIFICATION OF CONODONTS ULRICH AND BASSLER 33 



bends backward so strongly that it is almost parallel with the direc- 

 tion of the anterior half of the bar. Five or six denticles on the 

 anterior part of the bar, all curved backward. On the posterior 

 side of the main cusp eight or possibly nine denticles all straight, 

 relatively equal in size and length and paralleling in direction the 

 main cusp. 



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



Holotype.—Q^t. No. 11282, U.S.N.M. 



LONCHODINA SUBRECTA, new species 



Plate 5, figs. 4, 5 



Distinguished from L. typicalis by its much less bilateral develop- 

 ment and less regular arrangement of the denticles. The outer 

 denticles are much smaller than the inner ones and throughout are 

 very little curved so that their tips diverge with respect to the median 

 cusp. Two of the anterior denticles flanked by one or two smaller 

 denticles and the main cusp with two small denticles on the other 

 end approach the main cusp in size, whereas the posterior series con- 

 sists of four much smaller and nearly equal denticles, thus causing 

 the lack of bilaterality. 



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

 . C oty pes.— Cixt. No. 11283, U.S.N.M. 



LONCHODINA DELICATULA, .y^w species 



Plate 5, fig. 11 



Curvature of bar about as in L. typicalis, which it resembles in 

 general and from Avhicli it differs as it does from all other species of 

 the genus here recognized in the exceeding slenderness and wide sep- 

 aration of the denticles. The main cusp shares in this slenderness 

 and is moreover somewhat sharp edged. The denticles are more 

 nearly of a uniform size than any of the species to which it is allied. 



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



Holotype.—C2Lt. No. 11284, U.S.N.M. 



LONCHODINA PERARCUATA, new species 



Plate 5, fig. 10 



Bar horseshoe shaped, the anterior half with about nine rather 

 rapidly tapering curved denticles. The main cusp in the middle of 

 the curved bar, a small denticle next, succeeded by two nearly equal- 

 ling the main cusp in size and finally by two very small ones. 



The outstanding characteristic of this species is the exceeding 

 curvature of the bar. In other respects it reminds of L. hilateralis 



