316 APPENDIX. 
combine fossil teeth found separated, in such a manner as to leave no doubt about their specific 
identity. Several teeth of a very interesting species of Oxyrhina are found among the speci- 
mens of fossils brought by Mr. Blake from California, and its resemblance to the O. . 
of the Mediterranean is very striking. But, the character by which they differ most strikingly 
from the living species, and the fossils already described, consists in the greater flatness of the 
teeth, as compared with their width. Some of these are straight, and others slightly bent 
backwards. This species I propose to name O. plana. Several species of this genus have been 
described from the Atlantic States by Dr. R. W. Gibbes. 
8. o. TUMULA, Agassiz, Pl. I., figs. 26, 27, 36, 37, 42-44.— The existence of.a second species 
of the genus Oxyrhina in the Tertiaries of California is indicated by several teeth remarkable 
for the size and thickness of the roots, as compared with the length of the crown. The speci- 
mens agreeing in this character differ greatly in size, and yet not more so than may be seen in 
the same jaw of our living species. Found with the preceding by Mr. Blake. 
LAMNA. \ 
9. L. CLAVATA, Agassiz, Pl. I, figs. 19, 20, 21.—Two teeth from Ocoya creek indicate the 
existence in California of a species of Lamna allied to Z. cuspidata of the European Miocene, 
from which it differs, however, by its smaller size, its shorter and narrower crown, in which 
respect it agrees more with L. Hopei of Sheppy. The crown, however, is less arched than in 
the latter. The posterior surface is smooth, as in L. cuspidata. Found with the preceding in 
the Tertiary formation of Ocoya creek. 
. 10. r. ORNATA, Agassiz, Pl. I, fig. 28.—A second species of Lamna has been brought from 
California by Mr. Blake. It occurs in the sandstone of Navy Point, Benicia, and is allied to 
L. elegans, Agassiz.—(See Recherches sur les Poissons Fossile, vol. 3, p. 289.) It is, however, 
a smaller species, and tapers more gradually; while in Z. elegans it tapers more suddenly near 
the top, and the folds of the enamel on the inner side of the tooth are coarser. The base of the 
tooth is more compressed than in L. elegans, in which respect the tooth resembles more L. 
acuminata. The small tooth found with the specimen may be one of the lateral teeth of the 
same species ; but it is difficult to determine this without a mieroscopal examination of its struc- 
ture. These fossils are unquestionably of Tertiary age. L. elegans is found in the Calcaire 
grossier, in the environs of Paris, and in the London clay at Sheppy. The same species is also 
found fossil in the Crag, having been transported with the remains of many other species from 
the London clay. Several species of this genus have been described from the Atlantic States by 
Dr. R. W. Gibbes. ۱ 
ZYGOBATES, Agassiz. 
11, ZYGoBATES ? PL I, fig. 31-35. A fragment of a tooth of the genus Zy gobates - 
interesting, inasmuch as it shows that this genus of the order of the family of Skates with 
pavement-like teeth to have occurred in California during the Tertiary period ; though the 
fragment of the tooth before me is too imperfect to allow the species to be identified. It may 
not be out of place to remark that no species of this genus or the allied genera Rhinoptera, 
ZEtobates, or Myliobates, have thus far been found in the Pacific ocean. 
Several fragments of bone found with the teeth at Ocoya creek (Posé creek) belong 
family of Scomberoides, but are too imperfect to admit of being identified. 
to the 
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