SCIENTIFIC SUMMARY. 
369 
Among them is a new species of Gastornis (G. Fdwardsix). Among Reptiles, 
freshwater and marsh tortoises abound, belonging to the genera Emys , 
Dermatemys, and Platemys, the last now confined to the Southern hemi- 
phere. Several species of Trionyx occur, and also a new type of Tor- 
toise, resembling Trionyx in the granular state of its carapace, and 
the Emydes in the marginal plates, and the structure of the plastron. Both 
true Crocodiles and Alligators have left their remains in these deposits, and 
some of them appear to have been of large size. Among the Crocodiles one 
seems to approach the Gavial in the structure of the lower jaw; whilst 
another presents analogies with certain Secondary Crocodiles in its dental 
structure. Of the Lacertilian forms some have concavo-convex vertebrae ; 
whilst others, with the vertebrae biconcave, or flat on both surfaces, would 
seem to belong to the Geckotidae, a group now including only the Geckos, but 
more largely represented in Secondary formations. A new genus Simcedo- 
saurug, seems to present a combination of Lacertian and Crocodilian cha- 
racter, and was probably aquatic in its habits. Remains of snakes indicate 
that those animals may have attained a length of ten or twelve feet. The 
Batrachia are represented by the genus Bufo. The remains of Teleostian, 
Ganoid, and Chondropterygian fishes have been detected. Among the 
Ganoids the author mentions Phyllodus, Lepidosteus, and Amia ; and of the 
cartilaginous fish he cites Chimaeras, Sharks, and Rays. Remains of Mol- 
lusca, fragments of Insects, Entomostraca, and Foraminifera, together with 
many traces of plants, also occur in the Lower Eocene of the neighbourhood 
of Rheims. — ( Compte Bendus deV Assoc. Prang., 1879, p. 585.) 
British Fossil Cephalopoda. — We understand that the Rev. J. F. Blake, 
F.G.S., assisted by grants from the Government Research Fund administered 
by the Council of the Royal Society, has now brought the first stage of his 
investigations upon the British Fossil Cephalopoda to a close. He has com- 
pleted his work upon the Silurian forms, which he proposes shortly to 
publish, prefixing to his descriptions of the genera and species a general in- 
troduction on the anatomy of the group, the structure and modification of 
the shells, &c. The number of Silurian species recognized by him is nearly 
two hundred. The work will form a volume of about four hundred 4to 
pages, illustrated with thirty-two plates. It will be published by sub- 
scription. 
Mesozoic Mammalia. — At the close of his description of some very in- 
teresting Jurassic Mammalian remains from the Rocky Mountains {American 
Journal, September 1880), Prof. Marsh adds the following general remarks, 
which may be taken into consideration side by side with the facts detailed 
in Dr. Lemoine’s account of the Mammalia of the Lower Eocene of 
Rheims : — 
‘ Mesozoic Mammals have been very generally referred hitherto to the 
Marsupialia. An examination of all the known remains of American Meso- 
zoic Mammalia, now representing upwards of sixty distinct individuals, has 
convinced the writer that they cannot be satisfactorily placed in any of the 
present orders. This appears to be equally true of the European forms which 
the writer has had the opportunity of examining. With a few possible 
exceptions, the Mesozoic Mammals best preserved are manifestly low gene- 
ralized forms, without any distinctive Marsupial characters. Not a few of 
