STUDIES IN FORAMINIFERA 



215 



151°25' W., along the Chandler River, near the Schrader 

 anticline, southeast of Umiat, in the northern foothills 

 of the Brooks Range, northern Alaska. Collected by 

 R. L. Detterman, 1948. 



Unfigiu-ed paratypes (USNM P4513) taken 2,460 

 feet below the top of the Sentinel Hill member of the 

 Schrader Bluff formation (field sample 47 A St 30), on 

 the north bank of the Colville River, about 7K miles 

 southwest of the confluence of the Chandler and Col- 

 ville Rivers atlat. 69°25' N., long. 151°48' W., in the 

 northern foothills of the Brooks Range, northern 

 Alaska. Collected by Karl Stefansson, 1947. 



Figured paratype (USNM P4514) and unfigured para- 

 types (USNM P4515) from a core at 609-615 feet, all 

 from the Sentinel Hill member of the Schrader Bluff 

 formation, in Sentinel Hill core test 1, at lat. 69°35'48" 

 N., long. 151°28'09" W., on the west bank of the Col- 

 ville River, Arctic Coastal Plain, northern Alaska. 



Unfigured paratypes (USNM P4517) from a core at 

 499-509 feet and vmfigured paratypes (USNM P4518) 

 from a core at 519-529 feet, all from the Seabee forma- 

 tion, 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. 



Unfigured paratypes (USNM P4519) from 1,290 feet 

 below the top of the Seabee formation (field sample 47A 

 Wb 172), along the Nanushuk River about 15 miles 

 south of the confluence of the Nanushuk and Anaktuvuk 

 Rivers, at approximately lat. 69°04' N., long. 150°55' 

 W., in the northern foothills of the Brooks Range, 

 northern Alaska. CoUected by E. J. Webber, 1947. 



Family Nodosariidae Schidtze, 1854 



Genus Marginulina d'Orbigny, 1826 

 Marginulina gatesi Tappan, new species 



Plate 68, Figures 7, 8 



Test free, robust, early portion with a curved axis, 

 but not a distinct coil, later uncoiled and rectilinear, 

 rounded in section; chambers few in number, those of 

 the curved early portion increasing very rapidly in 

 size as added, later three or four chambers uncoiled 

 and of more nearly equal size, considerably overlapping, 

 inflated, final chamber about twice the height of the 

 penultimate one; sutiu-es distinct, somewhat con- 

 stricted, radial in the early portion, nearly horizontal 

 in the uncoiled part of the test; wall calcareous, finely 

 perforate, surface ornamented with about 12 low and 

 widely spaced vertical ribs; aperture radiate, terminal 

 on the final chamber, eccentric, somewhat closer to the 

 dorsal angle and slightly produced. 



Length of holotype 0.52 mm., breadth 0.26 mm. 

 Paratypes range from 0.36 to 0.68 mm. in length. 



Remarks: Marginulina gatesi, new species, differs 

 from M. radiata Terquem in having fewer and wider 

 spaced ribs and in these being vertical rather than 

 crossing the chambers obliquely. The present species 

 is also much more robust. 



This species occurs in the Grandstand and Topa- 



goruk formations. The specific name is in honor of 

 G. L. Gates, chief of the Alaskan Geology Branch, 

 U. S. Geological Survey. 



Types and occurrence: Holotype (USNM P4522) 

 and unfigured paratypes (USNM P4523) from a core 

 at 273-283 feet, unfigured paratypes (USNM P4524) 

 from a core at 238-256 feet, unfigured paratypes 

 (USNM P4525) from a core at 293-303 feet, unfigiu-ed 

 paratype (USNM P4526) from a core at 338-348 feet, 

 figured paratype (USNM P4527) and unfigured para- 

 types (USNM P4528) from a core at 523-533 feet, un- 

 figured paratypes (USNM P4529) from a core at 

 900-910 feet, all in the Grandstand formation; and un- 

 figured paratype (USNM P4530) from a core at 1,080- 

 1 ,087 feet in the Topagoruk formation ; all from Simpson 

 test well 1, at lat. 70°57'05" N., long. 155°21'45" W., 

 west of Cape Simpson, northern Alaska. 



Unfigured paratype (USNM P4531) from well cut- 

 tings at 410-420 feet in the Grandstand formation, in 

 Simpson core test 10, at lat. 70°57'34" N., long. 155° 

 17'27" W., in the vicinity of Cape Simpson, northern 

 Alaska. 



Unfigured paratype (USNM P4532) from the Grand- 

 stand formation (field sample 47A Dt 228) taken about 

 4% miles airline upstream from the mouth of Fossil 

 Creek, a small, north-flowing tributary to the Colville 

 River, at lat. 69°19'20" N., long. 152°28' W., in the 

 northern foothUls of the Brooks Range, northern 

 Alaska. Collected by R. L. Detterman, 1947. 



Genus Dentalina d'Orbigny, 1826 



Dentalina? dettermani Tappan, new epccies 



Plate 68, Figures &-12 



Test free, consisting of inflated somewhat elongate 

 or ovate chambers, much constricted to a slender 

 tubular neck at each end, and probably originaUy 

 consisting of a number of these chambers uniserially 

 arranged, but in an arcuate series as the chambers 

 may be slightly asymmetrical, with the apertiiral neck 

 eccentric; sutures consisting of greatly constricted 

 neck, but chambers of all specimens observed have 

 been broken apart at these constrictions; wall calcare- 

 ous, finely perforate, hyaline, surface smooth or finely 

 hispid; aperture at the end of the tubidar neck, rounded. 



Length of chamber of holotype 0.65 mm., breadth 

 0.34 mm. Paratypes range in chamber length from 

 0.29 to 0.55 mm. 



Remarks: The generic placement of this species is 

 questioned, as no complete tests have been found, 

 undoubtedly because of the fragile nature of the con- 

 necting necks between the inflated chambers. The 

 asymmetry of the single chambers, their size range, 

 and the invariable presence of a broken neck at one or 

 both ends strongly suggest that these chambers repre- 

 sent an elongate, fragile Dentalina, whose chambers 

 were isolated in preservation. 



Superficially D.f dettermani, new species, resembles 

 Lagena hauterivmna Bartenstein and Brand but differs 

 in the presence of a connecting neck at both ends of 



