Foraminifera from Japan — As AND 
159 
Both the dominant genera of this assem- 
blage, Glohotruncana and Silicosigmoilina, 
are recorded from Japan for the first time. 
Their range in Europe and North America is 
restricted to Upper Cretaceous formations. 
Several of the species recorded are widely dis- 
tributed in the Upper Cretaceous strata of 
other regions, and four are described as new. 
Silicosigmoilina futabaensis occupies a posi- 
tion in the Japanese assemblage comparable 
to that of S. calif ornica in the Upper Creta- 
ceous of California. Glohotruncana canali- 
culata is found in abundance in Europe and 
the Gulf Coast region of the United States, 
but more rarely in California. 
The writer is indebted to Lt. Col. Hubert 
G. Schenck, chief of Natural Resources Sec- 
tion, General Headquarters, Supreme Com- 
mander for the Allied Powers, and professor 
of geology at Stanford University, California, 
under whose supervision and encouragement 
the present investigation was conducted; to 
Mr. Leo. W. Stach, head of the Petroleum 
Branch, Natural Resources Section, who was 
responsible for editing the manuscript; to the 
Hisanohama Coal Mining Co., which offered 
the core samples for study; to Dr. K. Hatai, 
Tohoku University, for advice and assistance 
during the investigation. 
All specimens described herein are depos- 
ited in the collection of the Institute of Geol- 
ogy and Paleontology, Tohoku University, 
Sendai, Japan. Catalogue numbers of regis- 
tered specimens are indicated in the text by 
the prefix IGPS. 
Family SILICINIDAE 
Genus Silicosigmoilina Cushman and 
Church, 1929 
Silicosigmoilina futabaensis Asano, n.sp. 
PL 1, Figs. 6a, b\ la, b 
Test compressed, oval in side view, periph- 
ery subacute; chambers planispiral in earlier 
and sigmoidal in later stages; sutures indis- 
tinct, but fairly well marked between later 
chambers, not deeply depressed; wall finely 
arenaceous, firmly cemented with siliceous 
cement; aperture simple, without a tooth; 
white or light gray in color. Length to 0.7 
mm.; breadth 0.5-0.3 mm.; thickness 0.2- 
0.3 mm. 
Holotype: IGPS 67016. 
This species is related to Silicosigmoilina 
calif ornica Cushman and Church, a species 
found abundantly in the Upper Cretaceous of 
California, but the Japanese species has a 
more compressed test. 
Family TROCHAMMINIDAE 
Genus Trochammina Parker and Jones, 
1859 
Trochammina hisanohamaensis Acano, n.sp. 
PI. 1, Figs. 8a-c 
Test much compressed, planoconvex, dor- 
sal side flat; ventral side slightly convex, um- 
bilicate; chambers 4 or 5 in last coil, earlier 
chambers indistinct; sutures indistinct except 
for later ones which are somewhat depressed; 
wall finely arenaceous, smooth. Diameter to 
0.6 mm. 
Holotype : IGPS 67017. 
Trochammina texana Cushman and Wa- 
ters, from the Upper Cretaceous of the Gulf 
Coast region, is similar to this new species, 
but has less depressed sutures and the cham- 
bers have no raised borders. 
Family LAGENIDAE 
Genus Robulus Montfort, 1808 
Robulus futabaensis Asano, n.sp. 
PL 1, Figs. 12*, b 
Test closely coiled, moderately compressed, 
periphery acute or with a slight keel; cham- 
bers distinct, of uniform shape and increasing 
gradually in size, 7 or 8 in adult coil; sutures 
distinct, gently curved, becoming thick and 
raised toward umbilical area; wall smooth; 
