792 APPENDIX I 
Fig. 7, plate 15, represents an Ostreea from Truxillo, observed in the same collection 
at Lima. It is supposed to be tertiary. As we are not fully informed as to its mode of 
occurrence, we pass it by with this bare mention. 
Ill FOSSILS FROM NORTHWESTERN AMERICA. 
1. CETACEAN, 
Vertebree and fragments of other cetacean bones are occasionally found in the argilla- 
ceous sandstone of Astoria, (south side of the Columbia, about thirteen miles above its 
mouth,) and may be picked up along the shores of the river. Plate 16, fig. 1, represents 
one of the vertebree, of its natural size. 
2. FISHES, 
In the same region, just alluded to, we obtained the remains of four species of fossil fish. 
Figure 2, plate 16, represents a species allied to Trigla. It was found (as figured) in 
a concretion of limestone in the argillaceous rock. The surface of the mass having been 
worn on the river’s banks, the skeleton is exposed to view in the manner here shown. A 
large part of the vertebral column remains, and portions of the bones of the head, with 
parts of the pectoral fin, and many of the scales. The bones and scales have the colour, 
translucency and hardness of tortoise shell. The scales have the surface strongly striated 
below the central line, and a pectinate lower margin; they are also concentrically and 
neatly marked with delicate lines of growth. The striated character is owing to thin 
trenchant ridges, which have a serrulate edge. The form is suborbicular, the larger 
approaching quadrate, and the smaller somewhat hexagonal ; the lower margin is strongly 
arcuate. The vertebra are longer than their breadth. 
Figure 3, plate 16, is another species, of which we have only a cast in a fragment of 
argillaceous slate. ‘The genus we have not made out. 
Figures 1, 2 a, 2 6, plate 17, of natural size, represent large vertebrae from the same 
locality. Those of the latter two figures pertain, as we suppose, from the very open tex- 
ture and fine calcareous plates, to a species of shark. The first is also very open in its 
texture, and owes its apparent solidity to the limestone with which it is mineralized, In 
the specimen, edges of vertical plates are seen occasionally on the sides, (as on the left 
side of the figure, and also on the back top edge towards the right,) and on the broken 
surface, (front of figure,) there are a few irregular oblique plates either side of the centre, 
as represented ; all indicating a very coarsely cellular structure. 
3. CRUSTACEA. 
CALLIANASSA OREGONENSIS (Dana).—Remains of a single species of crustacea are 
found in the calcareous concretions of the argillaceous rock near Astoria, (see plate 17, 
fig. 3.) It is related to Callianassa, a genus whose species live mostly in holes on muddy 
shores. The compressed form and nearly equal length and breadth of the hand and 
carpus, are characteristic of this family of Crustacea. 
