74 G. M. DAWSON ON A NEW SPECIES OF 
same way corresponds very closely with the Tertiary and modern 
Nummaulites. 
In the arrangement of the pillars uniting the folds of the lamina, 
the spongy ingrowth filling the chambers, and in other points, this 
Loftusia bears a striking resemblance to some forms of Stromatopora.. 
It differs, however, in its regularly spiral character, and in the fact 
that no pores have been observed to traverse the “primary” lamina. 
It is scarcely probable, however, that the organic connexion between 
the different parts of the Loftwsta was maintained only in directions 
parallel to the circuitous course of the lamina. 
Genus Lorrusta, Brady. 
LoFTysiA COLUMBIANA, Sp. Roy. 
Test oval; circular in transverse section; the ends rounded or 
very obtusely spindle-shaped; chambers many, narrow ; septa very 
oblique, more nearly parallel to the sides of a cylinder than is the 
primary lamina; primary lamina and septa, or “secondary” in- 
growths, supported by pillars or “ tertiary ” ingrowths ; pillars nu- 
merous, arranged in parallel lines transversely and longitudinally, 
expanding laterally at their distal extremities to form imperfect cham- 
bers, which are filled with a loose, granular, cancellated growth. 
Exterior of test frequently becoming irregular and acervuline. 
19 
Length of test about 53°, of an inch, width of test about 1% of an 
inch ; intervals between successive folds of the adult primary lamina 
about +4, of an inch. 
Carboniferous Limestone, Marble Canon, British Columbia. 
DESCRIPTION OF PLATE JVI. 
Fig. 1 represents portion of a transparent section, nearly at right angles to 
the longer axis of the Foraminifer. The test is represented by the 
darker shading, while more transparent calcite fills the chambers. The 
primary lamina is designated by a, and is seen to be thickened by the 
spongy ingrowth. 6 designates one of the more perfect secondary 
growths or septa. Many of the tertiary ingrowths end proximally 
before reaching the inner lamina; this may arise in some cases from 
the slight obliquity of the plane of section to the direction of their 
axes. That the section is not truly through the centre of the form is 
seen at d, where it becomes tangential to the inner layer, and exhibits 
a portion of the primary lamina in plan. (X 25.) 
Fig. 2 is a portion of a longitudinal section of the outer part of the test. a 
designates the primary lamina ; c the tertiary processes or pillars. e, f, 
& g refer to the acervuline or irregular exterior portion, well deve- 
loped in this specimen. At ¢ an irregular tier of chambers has been 
formed, which pass outwards in some places almost imperceptibly into 
d, a spongy or cancellated mass, which is generally limited exter- 
nally by a more or less definite wall, g. The secondary growths, or 
septa, are not seen in this section, and tnis is very frequently the case 
in longitudiual sections. It arises partly from the greater transpa- 
rency of these as compared with the thickened floors and the pillars, and 
apparently partly also from the circumstance that they are in reality 
more fragile. (x 25.) 
Fig. 3 represents a portion of a longitudinal tangential section, which is very 
- instructive, as showing nearly all parts of the test. This may profi- 
