1352 GEOLOGICAL SURVEY OF THE TERRITORIES. 
not thought to indicate even a permanent varietal difference. The de- 
tails of all these far western examples being the same as those of the 
type specimens, the original description is here repeated with only 
slight change. 
Corallum ramose, the branches comparatively few and not’ veuyae 
materially in size from that of the portions from which they spring 
transverse section triangular; all three sides poriferous; the edges 
moderately sharp and sometimes a little irregular ; the laminar axis con- 
sisting of three divisions which end respectively at the three edges and 
meet and blend at the center of the corallum ; pores well developed, 
but they are not arranged in the regular order that i is common in this 
genus, nor are they bounded by any longitudinal or transverse lines or 
ridges. Their mouths are moderately prominent, shghtly oval, the di- 
rection of the longer diameter of each being subject to no regularity. 
This species differs from typical forms of Ptilodyctia in having three 
flat or concave sides instead of two convex ones, in the axis being 
consequently tripartite, and in the irregular disposition of the pores 
upon the surface. 
BRACHIOPODA. 
Genus PRODUCTUS Sowerby. 
PRODUCTUS GIGANTEUS Martin. 
Plate 36, figs. 1 a, b, and & 
Among a small collection of fossils sent to the National Museum by 
Mr. Ludwig Kumlein, of the United States Fish Commission, from the 
valley of McCloud River, Shasta County, California, are three or four 
examples of a very large ’ Productus which I am unable to distinguish 
from P. giganteus, the well-known type species of the genus, as it is exten- 
sively known in European strata. They are preserved in a hard, dark- 
colored argillaceous rock, which is partly metamorphosed, and they are, 
therefore, somewhat imperfect; but some portions of them show the ~ 
characteristics of the species very plainly. The largest of these Cali- 
fornia examples was, when perfect, quite equal in size to the larger 
European examples of P. giganteus, having had a transverse diameter, 
near the hinge border of not less than 140 ‘millimeters, or 54 inches. 
The other fossils associated with them are too imperfectly preserved 
for specific determination, but the genera Streptorhynchus, Fenestetla, 
Spireg gera, Camarophoria, Allorisma, and Huomphalus were more or less 
satisfactorily recognized. The Streptorhynchus is apparently S. erinistria 
Phillips sp. Besides the specimens of P. giganteus there are two or three 
examples of a smaller Productus which closely resemble P. nebrascensis 
Owen, but they are very imperfect. They all together plainly indicate 
the Carboniferous age of the strata from which they come; which fact 
was also previously ‘known through the reports of Trask and Whitney. 
This, so far as I am aware, is the first discovery of P. giganteus in 
American strata. It is not a little remarkable that it should be found 
in the western portion of the continent, and not in the middle and east- 
ern portions, where the Carboniferous system is so well developed, and 
where several European species of brachiopoda are recognized. 
