STUDIES nST FOEAMINIFERA 



213 



Unfigured paratypes (USNM P4448) from a core at 

 472-481 feet in the Grandstand formation, in Umiat 

 test well 3, at lat. 69°23'16" N., long. 152°05'14" W., 

 north of Umiat, in the northern foothills of the Brooks 

 Range, northern Alaska. 



Unfigm-ed paratype (USNM P4449) from well cut- 

 tings at 1,090-1,100 feet and unfigured paratype 

 (USNM P4450) from well cuttings at 1,180-1,190 feet 

 in the Topagoruk formation, in South Barrow test 

 well 1, at lat. 71°19'12" N., long. 156°42'15" W., 

 southwest of Point Barrow, northern Alaska. 



Unfigured paratype (USNM P4451) from well 

 cuttings at 750-760 feet in the Topagoruk formation, 

 in South Barrow test well 2, at lat. 71°15'15" N., 

 long. 156°37'55" W., south-southwest of Point Bar- 

 row, northern Alaska. 



Psamminopelta gubcircularis Tappan, new species 

 Plate 67, Figures 8-10 



Test free, discoidal, planispiral, each chamber a half 

 coil in length, chambers very narrow and elongate, 

 nearly circular in section; sutures distinct, depressed; 

 wall finely agglutinated, smoothly finished; aperture 

 at the end of the last tubular chamber, no tooth visible. 



Length of holotype 0.31 mm., greatest breadth 0.26 

 mm., thickness 0.04 mm. Paratypes range from 0.18 

 to 0.34 mm. in length. 



Remarks: Psamminopelta subcircularis, new species, 

 differs from Miliammina manitobensis Wickenden in 

 being much smaller, about one fourth as large, in being 

 discoidal rather than fusuline in shape, and in lacking 

 the quinqueloculine development of Miliammina. It 

 somewhat resembles Massilina glutinosa Cushman and 

 Cahill, but is about one-half as large, with narrower 

 chambers and more nearly circular outline, planispiral 

 development, and arenaceous wall, insoluble in acid. 



The species occurs in the Grandstand and Topagoruk 

 formations. 



Types and occurrence: Holotype (USNM P4452) 

 and figured paratype (USNM P4453) from a core at 

 361-366 feet in the Grandstand formation, in Umiat 

 test well 3, at lat. 69°23'16" N., long. 152°05'14" W., 

 north of Umiat, in the northern foothills of the Brooks 

 Range, northern Alaska. 



Figured paratype (USNM P4454) and unfigured 

 paratype (USNM P4455) from a core at 499-509 feet, 

 unfigiired paratype (USNM P4456) from a core at 

 522-524 feet, unfigured paratypes (USNM P4457) from 

 a core at 770-780 feet, aU from the Grandstand forma- 

 tion; and unfigured paratype (USNM P4458) from 

 well cuttings at 4,010-4,020 feet in the Topagoruk 

 formation; all in Umiat test well 2, at lat. 69°23'04" N., 

 long. 152°05'01" W., north of Umiat, in the northern 

 foothills of the Brooks Range, northern Alaska. 



Unfigured paratypes (USNM P4459) from a core at 

 1,424-1,434 feet, unfigiu-ed paratypes (USNM P4460) 

 from a core at 1,693-1,703 feet, and imfigured para- 

 types (USNM P4461) from a core at 1,713-1,723 feet, 

 all from the Grandstand formation, in Umiat test well 



1, at lat. 69°23'52" N., long. 152°19'45" W., west of 

 Umiat, in the northern foothills of the Brooks Range, 

 northern Alaska. 



Family Trochamminidae Schwager, 1877 



Genus Trochammina Parker and Jones, 1859 



Trochammina eilete Tappan, new species 



Plate 68, Figures 1, 2 



Test free, discoidal, trochoid but with a flattened 

 spire, periphery rounded; chambers numerous, about 

 10 to 14 in the final whorl of adult specimens, of greater 

 height than breadth and appearing cuneate in side 

 view; sutures distinct, thickened, somewhat depressed, 

 radiate; wall finely agglutinated, with considerable 

 cement, surface smoothly finished; aperture a low arch 

 at the base of the final chamber face, against the peri- 

 phery of the previous whorl. 



Greatest diameter of holotype 0.52 mm., thickness 

 0.17 mm. Paratypes range from 0.21 to 0.68 mm. in 

 diameter. 



Remarks: Trochammina eilete, new species, differs 

 from T. sablei Tappan from the Jurassic in being about 

 twice as large, in having many more chambers per 

 whorl, and in the chambers being wedge shaped rather 

 than inflated and subglobular. This species is char- 

 acteristic of the Torok formation and the equivalent 

 Fortress Mountain formation. 



Types and occurrence: Holotype (USNM P4483) 

 and unfigm-ed paratypes (USNM P4484) from field 

 sample 49A Ch 45 and unfigiu-ed paratypes (USNM 

 P4485) from field sample 49A Ch 44, both taken 180 

 feet (approximate) below top of the Torok formation 

 in Ravine Basin, Kukpowi-uk River area, at lat. 

 68°46'30" N., long. 163°07' W., in northwestern 

 ^Vlaska. Collected by R. M. Chapman, 1949. 



Figiu-ed paratype (USNM P4487) and unfigured 

 paratype (USNM P448S) from the Fortress Mountain 

 formation, in a section 1,150-1,750 feet above the base 

 (field sample 49A Pa 593), on the Kii-uktagiak River, 

 west of Castle Mountain, at lat. 68°35' N., long. 

 152°54' W., in the southern foothiUs of the Brooks 

 Range, northern Alaska. Collected by W. W. Patton, 

 Jr., 1949. 



Unfigured paratypes (USNM P4489) from 5,500 

 to 6,000 feet above the base of the Fortress Mountain 

 formation (field sample 49A Tr 562), on Castle Creek, 

 south-southwest of Castle Mountain, at lat. 68°32'05" 

 N., long. 152°49' W., in the southern foothills of the 

 Brooks Range, north Alaska. CoUected by I. L. 

 Taflleur, 1949. 



Unfigured paratypes (USNM P4482) from the Torok 

 formation (field sample 49A Tr 695), on the south 

 limb of the Ayiyak anticlinorium, on the Kiruktagiak 

 River, due north of Castle Mountain, at lat. 68°38'40" 

 N., long. 152°44' W., in the southern foothiUs of the 

 Brooks Range, northern Alaska. Collected by I. L. 

 TaiUeur, 1949. 



