AIM. ij classification; oi-' coxodonts— ulkjch and bassleu 31 



a view of the underside of the base; denticles more irre<i;idar and 

 farther separated. Main cusp sometimes not readily distinguished 

 from the denticles. 



The main characteristics of this genus are its outwardly bowed 

 xorm, the greater length and separation of the rounded needle-shaped 

 denticles, and their usually unsymraetrical arrangement. The boAV- 

 ing of the tooth is especially characteristic, this occurring in two 

 directions, upward and outward. 



Genotijpe. — L. tiipieaJis^ new species. 



Range. — Upper Devonian and Early Mississippian. 



LONCHODINA TYPICALIS. new species 



Plate 5, ligs. ], 2 



The curved and outwardly bowed bar is thin and carries on its 

 upper edge first a strong median cusp and on each side of this four 

 or five denticles outwardly increasing in length and thickness, the 

 lirst denticles being small and the others becoming two-thirds the size 

 of the main cusp. Ends of bar curved down but the anterior end 

 is longer and more downward projecting than the others. Lateral 

 denticles require more and more of a curve to assume the erect posi- 

 tion characteristic of their upi)er half. 



This species is especially characterized by the nearly equilateral 

 development of the denticles on each side of tlie main cusp, their 

 strength, erect habits of their tips, and their curvature increasing 

 successively away from the median cusp. 



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



Cotypes.—Qfit. No. 11276, U.S.N.M. 



LONCHODINA SEPARATA, new species 



Phite o, lig. 12 



In separation and relative uniform size of denticles allied to L. 

 delicatula but tooth on the whole shorter with fewer denticles on 

 each side of the main cusp and especially on tlie posterior side 

 (four on the anterior and only two or possibly three on the posterior 

 side). Also in that the denticles of the anterior half decrease rather 

 regularly in length outwardly whereas in L. delicatula they increase 

 in this direction. 



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



n olotype.— Ciii. No. 11277, U.S.N.M. 



LONCHODINA RECTIDENS, new species 

 Plate .5. figs. 18, 14 



Bar short, strongly curved and bowed, bearing long straight 

 diverging, closely arranged denticles with four rather small ones on 



