1884.] Geology and Paleontology. 919 
hundred new inscriptions. He is about to depart to determine 
the position of the mountain mass of Jebel Agée, and proposes 
to traverse the entire Hedjaz. The results of his first journey 
ie in preparation for publication by the Geographical Society of 
aris 
aa wD oe ee 
The Aval.—M. Konshin states as the result of his explorations 
that the immense depression of Sara-kamysh, in some places 2 
feet below the Aral, formed in a geologically recent time one basia 
with that lake, The fossils of this depréssion are identical with 
species found in the Aral and Caspian lakes and show that its 
waters were brackish or salt. The lake had an outflow into the 
pian. 
Cuina.—M. Hosie, who has made a journey of nearly 2000 
miles from Chung-King in Szo-chuan to Cheng-tu, capital of that 
province, and thence by Tali in Yunnan to Yunnan-Fu, returning 
y another route, states that the European maps of these districts 
are exceedingly defective, although fairly good native maps can 
procured. 
GEOLOGY AND PALÆONTOLOGY. 
THE ProroconcH oF CEPHALOPODA. —The accepted divisions 
of the Cephalopods have been founded by authors wholly upon 
characteristics of the adult form of the shell, whether straight, as 
in Orthoceras, curved, as in Cyrtoceras, coiled up with open 
whorls, as in Gyroceras, or with the whorls in contact, as in Nau- 
ti These modifications, together with the outlines of the 
aperture and other minor characteristics, have, heretofore, deter- 
mined thë group to which any given shell was referred. 
„ -9e examination of the young of all the closely coiled Nau- 
tiloidea shows them to be as a rule uncoiled, and in the earliest 
stages simply arcuate as in the adults of the group of the Cyrto- 
ceratites, and having a scar on the apex which represents the 
beginning of the stage in which the animal commences to con- 
Struct the true or secondary shell. The young of all the Ammo- 
noids have, on the contrary, with the marked exception of some 
patæozoic species and some varieties of species,closely coiled whorls 
at the corresponding stage of growth, and upon the apex is a tiny 
bag or embryo shell, which has been very appropriately called the 
Protoconch by Owen. 
In my Embryology of Cephalopods, Bulletin of Museum of 
Comparative Zodlogy, Cambridge, No. 5, Vol. 111, the position 
Was taken that the scar of the Nautiloidea showed that a proto- 
Conch had existed in the embryo of Nautilus, but had disappeared 
during the growth of the shell, the scar being uncovered by its 
removal. This supposition was endorsed by Professor Richard 
Owen, but rejected by Barrande, who insisted that the general 
ce of a protoconch was a fatal objection. There exists, 
however » On the apex of some Orthoceratites, an excrescence or 
