196 
AUG. F. FOEESTE 
Several additional specimens, consisting of a number of plates 
still attached to each other, were found at the same horizon. 
The Comar ocystites horizon is regarded as below the Kimms- 
wick strata exposed at the locality south of Thebes, Illinois, 
which were studied by Prof. T. E. Savage. 
Comar ocystites punctatus, from the Trenton of the Ottawa 
area, is remarkable for possessing pinuliferous free arms, with 
plates arranged in uniserial order (Ottawa Naturalist, 30, 1916, 
October, November, December numbers.) Uniserial recumbent 
fixed arms occur in Amygdalocystites and Canadocystis. Such 
uniserial arms seem to be characteristic of a restricted closely 
related group of cystids. At one time, this uniserial arrange- 
ment of arm plates was regarded by the writer as primitive. 
However, it is difficult to maintain this opinion in view of the 
fact that all early cystids whose arm structure is known have 
the biserial arrangement. Gogia prolifica Walcott (Cambrian 
Geology and Paleontology, IV, no. 3, 1917, p. 68), from the Lower 
Cambrian of British Columbia, and E ocystites (?) longidactylus 
Walcott, from the Middle Cambrian of Nevada have biserial 
arms. This is true also of Macrocystella mariae from the Upper 
Cambrian of Shropshire of England, and Lichenoides from the 
Cambrian of Bohemia. 
5. Clitambonites cf. diver sus Shaler 
Plate XXIII, fig. 6 
Only a single brachial valve of Clitambonites, exposing its in- 
terior, was exposed in the Kimmswick limestone, in the lower 
half of the Sanders Creek section, in Ralls County. 
An excellent pedicel valve was collected by D. C. Barton from 
the Kimmswick limestone at the Glencoe Lime and Cement Com- 
pany quarry, at Alincke, in St. Louis County. In this specimen 
the cardinal area rises 10 mm. above the hinge-line, the latter 
being 19 mm. wide, and the maximum width of the valve being 
24 mm. The cardinal area forms an angle of about 135 degrees 
with the plane of contact of the two valves. It is regarded as 
a new species, but more material will be necessary to differen- 
