36 PROCEEDINGS OF THE NATIONAL MUSEUM vol.68 



LONCHODINA7 PRONA, new species 



Plate 5, ns?. Id, 17 



Like L. projecfa but the main cusp is thicker and longer and the 

 other denticles more numerous, smaller, and closer together with 

 seven or eight in front and five behind the main cusp. In some re- 

 spects it is like L. subangulata but the anterior denticles are more 

 numerous and relativel^y smaller, the main cusp is much thicker and 

 sharp edged instead of rounded, and the posterior denticles fewer 

 with but five instead of seven or eight. 



Occu7^'ence. — Devonian (Rhinestreet) : Shaleton, N. Y. 



Cotypes.—C^i. No. 11293, U.S.N.M. 



LONCHODINA GENICULATA, new species 



Plate 4, ng. 15 



Like L. subangulata but the bar is even more sharply bent, the 

 angle being almost rectangular and the denticles on the anterior 

 part more sharply recurved, the main cusp being on a line with the 

 anterior half of the bar. The main cusp is relatively shorter and 

 somewhat sharp edged and the disproportion between its length and 

 the denticles on the posterior part of bar- is much less. The length 

 of all but the first of the six posterior denticles is nearly or quite the 

 same as that of the main cusp itself. The species resembles certain 

 forms of Prioniodina like P. suhcurvata but the bar is more strongly 

 bowed outwardly, thicker, and the denticles more equal in length 

 and all the lateral ones longer than in that species. In the bowing 

 of the bar this is a true Lonchodlna. 



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



Holotype.—Cfit. No. 11294, U.S.N.M. 



LONCHODINA DISCRETA. new species 



Plate 10, figs. 1, 2 



Based upon a young example and a large tooth of this species dis- 

 tinguished by the considerably curved bar and the denticles definitely 

 separated from each other by spaces one to three times their own 

 width. One subcentrally situated denticle may be called the main 

 cusp being relatively larger and longer than the others. This is two 

 to three times larger than the others and moderately recurved. 



6>ccwrrenc6.— Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



Gotypes.—C2it. No. 11014. U.S.N.M. 



