.\I AKN I. \\ II (llidl.OdlC.M, srnVKV 107 



pfscri jil inn. — "Tciili loliiist, ill liiiiiiiiL; li> a vui'y Uiv^i^ .«i/,f; crown 

 iiindcijiifly coiiiprcsscd, sliarply poiiitcil, with uiic Ijroad aciniiinatf pair 

 <il' lateral dent iclcs, ami. in llic >iii,-illi'r ti'i'lli. an ailililiniiai |)aii- nf nini-c 

 slciidci- dcnl icli'-. (Milci' (iii-nnal face Hal nv sli^dilly convex, without 

 ]'i)kU; inner lace .-numlli. liMier lace ol' llic root ]ir()iniiiont. and Tiuii'i- 

 tive foranii'ii not sunk in a i:i'ihi\c." Ai^assiz, 181."!. 



These very mhnst teeth attain a lar^-e size, the cr^wn .-onietiines meas- 

 ni-in,i;' ."i em. in hei:^-lit (ef. I'lale .W, I-'i^;-. I). Imt the majurity of speci- 

 mens dti not exceed .'! em. in l<ital lieiLiht. 'The anteri(Ji' teeth (Phite 

 XV. I'iu'. 1) are narrow and ereet. with rather deeply cleft root, and 

 frc(|nently w ith only one or no lateial denticles; they are sometimes cliffi- 

 cidt to (list in.unish I'l'om the anterioi- teeth of OiJaiihisjiis luacrotn. Tiie 

 lateral teeth are distinguished hy their broader, more compressed and 

 usually obliquely directed crowns. The small hindermost teeth are 

 often extremely broad-based, but liere as elesewhere in the jaws, much 

 individual variation oeeurs. It does not appear possil)le, however, to 

 recognize more than a single species in tlie American Tertiaries. Xu- 

 merons examples are found in tlie l-'ocene of ]\rai-vland. Virginia. Xew 

 Jersey, and the Carolinas. 



Occurrence. — Aqui.v Formatiox. Liverpool. Aquia Creek, ftlymont. 



Collcclinjis. — Maryland Geological Survey, Johns Hopkiiis I'niversity. 



Genus CARCHARODON Agassis. 



The teeth of Varcharodun attain enormous size, exceeding" those of all 

 other Selachian genera. They are triangular, usually erect, and re- 

 semble those of Oxyrliina and Olodus except tliat the edges of the com- 

 pressed crown are alwa3's serrated. Some species are without lateral 

 denticles, others have a single pair, serrated like the crown. The genus 

 enjoyed a world-wide distribution during the Eocene and Miocene, and 

 was exceedingly abundant in various localities of both hemispheres. In 

 the South Carolina Phosphate Beds the teeth are so numerous as to be 

 of no mean commercial importance. 



