.M\ini,\\lt (!i;()l,()(ilf.\l, SIUVKY '^37 



not rciiiaiii ((mstMiit, mhiic specimens having only ei^'lit co^tae hcluw 

 and as many as Iwrlvr aliovc; ])rimor(lial clianiljcr hullxni.s, acuininati', 

 tliouiili the spine is iVcipifiilly l)n)ken; se«;ni('iils rc;.Milar. less distinct 

 Ix'liiw. iiiai'l<('d l)y st rai;ilil , transverse septae; len;!!!! iinl<ni)\\ii hm Tra*:- 

 nieiils u\' nine eliand)ei's niea>nre ."') nun. 



This Xadosiiria has ijeen descrihctl from a nundx-r of 'I'ertiary de- 

 posits of Knrope and En^hind but is selchjni found in modern oceans, 

 though Sc 111 mill )ei'gei' mentions it from the Gulf of Gascony. 



It is, like all yoihisariii, not at all comnioii in the Eocene deposits of 

 the :\lid(lle Atlantic Slope. 



Orrurrence. — Naxjemoy Foi{M.\.tiox. Woodstock. Aquia Foi;ma- 

 Tiox. 3 miles west .of Leeland, 2 miles below Potomac Creek, 1 mile 

 southeast of Mason Springs, Upper Marlboro. 



Collections. — Johns Hopkins University. ^larylaiid Geological Survey. 



NODOSARIA COMMUNIS ( (VOrijignv ). 

 Plate LXII. Fig. 7. 



iJciitalina conunimix d'Orbiguy, 1820, Aim. Sci. Xat., vol. vii, p. 2.54. 



Dentalina communis Jones aud Parker, ISOO, Quart. Jour. Geol. Soc. London, vol. 



xvi, pi. xix, tigs. 2.5, 26. 

 Noclo.taria communU Brady, 1884, Chal. Kept., vol. ix, p. 504, pi. Ixii, tigs. 19-22. 

 Nodosaria communis Bagg, 1896, Bull. 141, U. S. Geol. Survey, p. HI. 

 X(ich>si(riii communis BaiTg, 1808, Bull. Amer. Pal., No. 10, p. 25. 



Description. — Test elongate, smooth, with depressed, oblique sej^ta; 

 primordial chamber larger than the one succeeding and in some of our 

 specimens acuminate; ultimate chamber, elongate, tube-like; transverse 

 section circular, aperture round, smooth, length 0.6 mm. The earlier 

 description of this species was based on a single young form but since 

 this time a number of other specimens have been found from Upper 

 Marlboro. The typical forms of this species have the sutures depressed 

 and the chambers all oblique, in some of the forms remarka1)ly so. 



This is one of the most common Nodosaria in both fossil and recent 

 state and has a world-wide distribution to-day. It includes a large 

 number of variously described species with oblique sutures such as D. 

 inornata, and D. hadenensis, d'Orbigny (Yienua Basin Monograph). I). 

 leqinnen Eeuss. T). suharcunfn Williamson and many others. 



