256 2'he American Geoloyist. October, 1895 
but it had been rejjeatedly re-sharpened, and that not by the more mod- 
ern methods of pressure with a bone, but by direct blows upon the 
edge, indicating its great antiquity. 
Prof. J. W. Spencer remarked that this gravel terrace is somewhat 
older than the stratified drift of the Connecticut valley. 
Prof. E. D. Cope noted a close similarity of this implement with stone 
implements found by him in Pleistocene beds in Oregon, and regarded 
them as most allied to Mousterian types. 
Dr. R. G. Haliburton suggested that implements might be deeply 
buried in gravel through the modern washing away and redeposition of 
the beds: but, in reply to this. Prof. Wright stated that the highest 
modern floods of the Ohio lack some thirty feet vertically of reaching 
the level of this terrace. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
Phylogeny of an Acquired Characteristic. By Alpheus Hyatt. 
(Ex. Proc. Am. Phil. Soc, vol.xxxii, no. 143, pp. .349-647. pis. 1-14, Aug., 
1894.) Anything bearing upon the inheritance and phylogeny of an ac- 
quired character is especially interesting in these days of active discus- 
sion upon the same and kindred topics, and the present paper is very 
opportune, since it approaches the svibject from a side which is quite 
impossible in ordinary biology. Few besides professor Hyatt can bring 
to bear for this purpose such an extensive knowledge of the development 
and phylogeny of recent and fossil forms of any single class of animals. 
Moreover, the cephalopods offer a wealth of material for the study of 
ontogeny and phylogeny: their geological history has been long, and a 
vast number of species has been described. The division Tetrabranchi- 
ata, now ranked as a subclass by the author, has furnished the richest 
material and has been made the subject of greatest study. One large 
order, the Nautiloidea, began and culminated in Paleozoic time, while 
the other, the Ammonoidea, began later in the Paleozoic, but culmina- 
ted and went out in the Mesozoic. It is seen, therefore, that an oppor- 
tunity is afforded for making parallel correlations in two related orders, 
having mvxch the same general type of form, through widely different 
geological ages. 
In the preliminary discussions professor Hyatt emphasizes the value 
of the shell as an expression of the external form of the animal as giv- 
ing what the adult internal soft parts alone cannot, viz., an accurate 
history of the changes and events in the organism from its embryonic 
stages through youth, maturity and old age to the time of its death. In 
brachiopods, gastropods, pelecypods and cephalopods the embryonic 
shell is at the apex, around which growth takes place, and, in well-pre- 
8»rved specimens, all the subsequent stages may be traced. A farther 
advantage in the cephalopods exists in the internal structures, princi- 
pally the siphuncle and septa. The former exhibits changes of struc- 
ture and position during the life of the animal, and the latter with their 
