13 
The specimen illustrated shows the beautiful arrangement of the septa. 
The cardinal septum along the shorter diameter of the corallum is extended 
beyond the centre, shortening the length of the septa in the fan-shaped 
arrangement of the two counter quadrants. The septa of the cardinal 
quadrants are gathered up with a twist into two little knots, hollow in 
the centre, looking like pores in the bottom of the cup cavity. The cardinal 
septum casts in its lot with the right-hand group, orienting the specimen 
with the cardinal septum facing the observer. The septa of the two 
counter quadrants also run to two centres, but if they are twisted in a 
knot it is not preserved. The long cardinal septum appears to be weakened 
by its length and lack of support and is often destroyed, the space between 
forming a distinct pseudo-fossula. 
Longitudinal sections did not prove very satisfactory. The septa can 
be traced to the centre, but any tabulae or dissepiments have been destroyed 
by secondary deposits. 
S . distinctum is easily identified when the septal arrangement is 
preserved. When it is not it is readily distinguished from other species 
by the semi-rhomboid form due to the elongated lateral diameter, and the 
position of the pseudo-fossula on the shorter diameter. The angle along 
the line of the cardinal septum suggests relationship with S. prolongation, 
one species seems to push out its growth laterally, the other along the 
cardinal septum, resulting in the different outline. Otherwise they are 
very similar. The pseudo-columella of S. distinctum is more projecting 
and the cellulose part of it is smaller and more simple. One well-preserved 
specimen of jS. distinctum shows the same tendency toward the develop- 
ment of the plate-like standards, though to a less degree than in S. pro- 
longatum. 
Horizon and Locality. Richmond: Beaverfoot. At several localities 
just east of Palliser pass, at the Stoddart Creek section, and at the Fairmont 
Springs section in Windermere district, Rocky mountains, British 
Columbia. 
Streptelasma patellum n. sp. 
Plate II, figure 1 
In size and general proportion similar to S. distinctum with subdued 
angles at the ends of the alar septa, and no angle outlining the cardinal 
septum. As in S. distinctum the shortest diameter passes through the 
cardinal septum, but this species differs from any other in having a flat, 
plate-like projection which appears to be a continuation of the central 
part of the cardinal septum, protruding upward into the cavity of the cup 
and tilted slightly backward toward the opposite wall. The plate is 
helmet-shaped, placed with the point up, though it is possible that its 
outline is not complete. 
Horizon and Locality. Richmond: Beaverfoot. Fifty feet above the 
base in a section at the head of Windermere creek, Stanford range, B.C. 
21215 — 2 
