196 



UNITED STATES NATIONAL MUSEUM BULLETIN 215 



giving the test a low conical appearance; sutures dis- 

 tinct, curved obliquely backwards on the spiral side, 

 radial on the umbilical side ; wall calcareous, finely per- 

 forate, entire surface may be hispid, but with early 

 spire most prominently spinose, final one or two cham- 

 bers may be somewhat more smooth; aperture a very 

 small interiomarginal, extraumbilical-umbilical arch. 



Holotype 0.23 mm. in diameter. 



Eemarks: Globorotalia trichotrocha, new species, is 

 one of a closely related group of species, all of small 

 size with flattened spiral side, rounded or subacute 

 peripheral angle and spinose surface. It differs from 

 0. conicotruncata Subbotina in its smaller size, fewer 

 chambers per whorl and narrower umbilicus. Globoro- 

 talia perdara, new species, difi'ers in having more lobu- 

 late periphery, and relatively high, subglobular cham- 

 bers which are evenly convex on the umbilical side with- 

 out a prominent umbUical shoulder, and in having a 

 less hispid surface; 6. reissi, new species, has a convex 

 spiral side, a more lobulate periphery, chambers evenly 

 roimded on the umbilical side, sutures nearly radial 

 instead of oblique on the spiral side. 



The specific name is from the Greek thrix, trichos, 

 hair, and trochus, wheel. 



Types and occurrence: Holotype (USNM P5365) 

 and figured paratype (USNM P5705) from the Aquia 

 formation, 3 to 6 feet above base of section exposed, 

 west bank of Potomac River, near mouth of Aquia 

 Creek, S. 10° E. of Brent Point on U. S. Geological Sur- 

 vey Nanjemoy Md.-Va. Quadrangle, 1:62,500, 1913, 

 reprinted 1945. Collected by A. R. Loeblich, Jr., and 

 Richard A. Page. 



Figured paratype (USNM P5690) from the Horners- 

 town formation, north bank of Shingle Run, a tributary 

 to Crosswicks Creek, 1.0 mUe north of New Egypt, 

 Monmouth County, New Jersey. Collected by A. R. 

 Loeblich, Jr., and Norman Sohl. 



Globorotalia troelseni Loeblich and Tappan, new species 

 Plates 60, Figuebs 4a-c; 63, Figures 5a-c 



Test free, medium sized, compressed trochospiral, 

 IK to 2 whorls visible on the spiral side with the early 

 spire somewhat depressed, umbilical side with an open 

 umbilicus with portions of earlier whorls visible within, 

 due to the tendency of the final whorl to uncoil slightly 

 and appear somewhat evolute, periphery subacute with 

 a slight keel, peripheral margin lobulate; 5 to 6 chambers 

 in the final whorl, moderately inflated, of nearly equal 

 breadth and height, increasing gradually ia size as 

 added ; sutures distinct, depressed, gently curved on the 

 spiral side, nearly radial on the umbilical side; wall cal- 

 careous, distinctly perforate, surface smooth; aperture 

 interiomarginal, extraumbilical-umbilical, a relatively 

 high arch extending to the periphery, bordered above 

 with a very narrow lip. 



Holotype 0.26 mm. in greatest diameter. 



Remarks: This species is characterized by its ten- 

 dency to become evolute, so that the early whorls are 

 visible from both the spiral and umbilical sides. It is 



closest in appearance to Globorotalia pseudomenardii 

 BoUi, differing in the evolute tendency, and more nu- 

 merous chambers, which are more equally inflated on 

 the two sides. It has been observed only in the 

 Nanafalia and Velasco formations. 



This species is named in honor of Dr. John C. Troel- 

 sen. University of Copenhagen, Denmark, in recogni- 

 tion of his work on the Paleocene and lower Eocene 

 Foraminifera. 



Types and occurrence: Holotype (USNM P5687) 

 from the Nanafalia formation (Ostrea thirsae beds), 56 

 feet above the Midway contact, in road cut 1.2 mile 

 east of Kimbrough Station and 0.2 mile east of the 

 Turkey Creek bridge, Wilcox County, Alabama. Col- 

 lected by A. R. Loeblich, Jr. 



Paratype (USNM P5896) from the Velasco forma- 

 tion, middle bed at road crossing of arroyo halfway be- 

 tween San Jose de las Rusias and Soto la Marina, 

 Tamaulipas, Mexico. Collected by R. Wright Barker. 



Globorotalia varianta (Subbotina) 



Plates 44, Figtires la-2b; 45, Figures 4a-o 



Globigerina varianta Subbotina, Trudy Vses. Neft. Naukno- 

 Issledov. Geol.-Razved. Inst., new ser., vol. 76, p. 63, pi. 3, 

 figs. 5-12; pi. 4, figs. 1-3; pi. 15, figs. 1-3. 



Test free, medium sized, low trochospiral coil of 

 approximately 2}^ whorls, umbilical side with small 

 and deep umbilicus; chambers subglobular and inflated, 

 increasing rapidly in size, 5 to 6 in the final whorl; 

 sutures distinct, constricted; wall calcareous, distinctly 

 perforate, surface prominently spinose, especially in 

 the early chambers, later chambers becoming less 

 spinose; aperture extraumbilical-umbilical, a high open 

 arch extending to the periphery and bordered above by 

 a subtriangular lip which is widest at its midpoint and 

 tapers toward the periphery and umbilicus. 



Hypotypes range from 0.23 to 0.40 mm. in diameter. 



Remarks: This species is similar in size and plan of 

 growth to G. pseudobulloides (Plummer) and has 

 probably been confused with that species in the past. 

 It differs in having a prominently spinose surface and is 

 less coarsely perforate. 



Types and occurrence : Figured hypotypes (USNM 

 P5707a,b) from the Mexia clay member of the WiUs 

 Point formation, in abandoned pit of the Mexia Brick 

 Works at Mexia, Limestone County, Texas. Collected 

 by A. R. Loeblich, Jr. 



Figured hypotype (USNM P6708) from the Matthews 

 Landing marl member of the Porters Creek clay at 

 Naheola Landing on the Tombigbee River, SEK, Sec. 

 30, T. 15 N., R. 1 E., 11 miles east of Jachin, Choctaw 

 County, Alabama. Collected by A. R. Loeblich, Jr. 



Globorotalia velascoensis (Cushman) 



Plate 64, Figures la-2c 



Pulvinulina velascoensis Cushman, Contr. Cushman Lab. Foram. 

 Res., vol. 1, pt. 1, p. 19, pi. 3, figs. 5a-c, 1925. 



Test free, trochospiral, spiral side flattened, umbilical 

 side with the chambers much elevated at the umbilical 



