136 
derei exists between the Mentor fossil, 
Margarita mudgeana Meek, and the Kiowa 
species, M. marcowana nobis; and here also it 
remains to be shown whether the difference is 
genuine or due to unlike conditions of preserva- 
tion. 
Ihave recently identified Nerinea acus, Roem., 
from the Champion shell-bed at Belvidere, the 
markings shownas in Roemer’s figure of the 
type. This, with the Lithophagus noticed below, 
brings the total number of Invertebrata known 
from this thin but remarkable shell-bed up to 
thirty-eight. This interesting occurrence of 
Nerinea acus further confirms Professor Hill’s 
earlier and my own constant later reference of 
the Champion shell-bed to the Fredericksburg 
formation, and to the Comanche Peak limestone 
in particular ; and the occurrence of the Litho- 
phagus in both the Champion and the Kiowa not 
only adds to the former evidence of a closely 
successional time-relation of the two formations, 
but also tends to emphasize the conclusion I 
have elsewhere announced, that the Kiowa is 
about equally related to Fredericksburg and 
Washita. 
The Lithophagus referred to is one of which I 
found several specimens in burrows in Serpula- 
knots in the Champion shell-beds, and which is 
assumed not to differ specifically from the 
‘ Lithophagus sp. nov.’ of Stanton, reported (in 
Hill’s ‘ Outlying Areas of the Comanche Series 
in Kansas, Oklahoma and New Mexico;’ Am. 
Journ. Sci. 38rd Series, Vol. L), as occurring in 
Gryphea-valves in the Hill and Gould collec- 
tions from the Kiowa shales at Belvidere, borings 
similar to those in the Serpula having been 
found by the writer in Gryphea-valves at the 
zone of transition from the Black Hill shale to 
the Fullington bed, a horizon intermediate in 
position between the two which have yielded 
the actual shells of Lithophagus. 
In 1893 I collected in the Comanche Peak lime- 
stone of south-central and north-central Texas 
several specimens of an apparently undescribed, 
heavy-ribbed species of Cyprina, to which I have 
given the manuscript-name Cyprina laticostata. 
I now recognize as belonging to this new species 
the cast which, in my ‘Study of the Belvidere 
Beds,’ Ireferred to Homomya alta, Roem. Thus 
the evidence for reference of the Champion 
SCIENCE. 
[N. 8. Von. VI. No. 134, 
shell-bed to the Comanche Peak limestone of 
the Fredericksburg division continually becomes 
clearer. 
Stratigraphic Names for Caprina and Caprotina 
(or Requienia) Bearing Beds of Northern Texas. 
In defining the Barton Creek limestone, a mem- 
ber of the Fredericksburg formation (American 
Geologist, XVI., 385), I fell into the error of in- 
cluding in it both the Caprina limestone and the 
Caprotina limestone of Shumard, whereas it was 
the former only (whose fauna includes both 
Caprina and Caprotina, or Requienia, with other 
genera of Chamidz and Hippuritide) that should 
have been included in the definition, and which 
was especially intended, this being the lime- 
stone that succeeds the Comanche Peak lime- 
stone, on Barton creek, in Travis county, Texas. 
It is the cap-rock of a number of buttes that 
carry remnants of the Fredericksburg formation 
in central and western Texas. The Caprotina 
limestone of Shumard is the Caprotina or Re- 
quienia bed that occurs in the upper Glen Rose, 
in the Brazos Valley, in the vicinity of Gran- 
bury, and which may be designated as the 
Granbury bed, to distinguish it from more or less 
similar beds elsewhere. Since proposing the 
name Barton Creek for the Caprina limestone 
of the creek thus named, I have observed that 
the name is quite similar to that of the Barton 
clays (Tertiary) of England. The similarity is 
the more unfortunate because increased by my 
inadvertently referring to the Texas bed in a 
shorter form, ‘ Barton,’ in formally defining it, 
immediately after having defined it in table as 
‘Barton Creek.’ Altogether, the considerations 
stated probably render either ‘Barton’ or 
‘Barton Creek’ untenable, and both terms are 
therefore here abandoned in favor of another. 
The same bed of Caprina limestone that occurs 
on Barton creek may be seen overlying the 
Comanche Peak limestone, in Stonewall county, 
Texas (where, as Messrs. Dumble and Cum- 
mings have shown, and as the present writer 
has later observed, it forms the cap-rock of 
Double mountain) ; and the name Stonewall 
limestone is therefore here proposed for it. 
F. W. CRAGIN. 
CoLORADO COLLEGE, COLORADO SPRINGS, COL., 
May 28, 1897. 
