Part II - State of New Jersey

158 CRETACEOUS FOSSILSis rounded and fairly obtuse but lacks a well defined mucro. The valneof the Sellatsky Index is ahout 4.5 mm.Tlie above discussed gnarrl ;~pproachcs most closely those of I:.ntl~ericnna Tar. attlericcc?~and 8. n~t~ericrnln var. intermedia. From thegui~rcls of the lat,ter variety it differs, ho~vever, in its regular, marked,and even apical tapering in the lateral uslieet, comhined with itsrounded and ohtose ;~pical end, an11 the considerably lesser dorsoventralflattening ant1 eo~npressio~~. From 6. nntoricat~a var. americotlfit,lle above discussed guard cliff'ers mainly in the considerably lesserrlorso-ventral flattening and compression and in its deeper al~,eolus. At.the same time the aho\.c discussed morphological characters of theguard, combined with its relatirely feeble seulptureil surface, ally it\vith such Eurasian Relen~nitclle forms as B. praecarsor Stolley Tar.nt~~c~onatifor~nis Jeletzky, 1955, sm;lll unnamecl variants of B. ~TLcrot~ntn(Schloth.) fro^^^ the zone of K. ~a~ccronntn mot. senior Nowt~ks. sir., ant1 R. ~t~~iero~lntn (Schloth.) mut. ~tlinor Jeletzky, 1951. As apossible intermediate form bet\vecn I:. ntnericnna rar. intern~edia ant1the abore mentioned Eurasian ileleartritella forrns this guard certainlyileserves attention. So close inclc$:(l, is its morpl~ological silnilarit,~ tosome of the guards of 13. pvnecuvsor Stolley rar. mao.onatiforn~is Jel.,I955 or to those of the above mentionefl 1lnn;lmed variants of K. IIIIIoo~lata(Schloth.) t,luat the ~vriter \vonl(l refer this New Jerseyan guardto one of them mere it not for the fact that its Sclratsky Inrles is only4.5 mm. This villue is ~vell below the values characteristic of the aforementionedEurasian Relctr~nitclln forms and does not differ materiallyfrom those el~aracteristie of B. an~erica?ba var. anlcric:n?~a ant1 B. an~et'icanavar. internbedin. Tllcrefore the Selvell guard appears to be nothingelse but a peealiar morpl~ological variety of B. altrerieana (s. 1.)perhaps transitional bet~veen K. nn~erien~la var. intermedia and theahove mentioned Eurasian Kele~trr~itella forms. In this connection it isinteresting to note that t,he Se\vell guard \vas found alone at a localityfrom which no other Bolon,trifel!a forms were available to the writer. Ithas been considered preferable not to give a formal varietal name totl~is guard until more specimens arc a~~iilable and its strt~tigral)hiealrelationships are clarified.Belemnitella americana (Morton) par. 13Plate 'ill, Figures 8a-8eA single i~rconrplete guard from an nnkno~vn loca1it.y in Netr drrseydiffers from all ot,her previously discussed varieties of K. ntncri~:~ri~ns. I. in its much shorter and sturdier guard and in the very pronouncerland even apical tapering of this latter in its lateral and \,entrill aspects.The alveolus is relatively deep? judging by its preserved lo~ver part:its angle in the dorso-ventral plane is 18-19°. The Schatsky Index is4.5-5.0 mm. The bottom of the alveolar fissnre is slightly concave towardthe apical part of the guard and short, forming a 45-50' angleNEW JERSEY GEOLOGICAL SURVEY