REVIEWS 289 
this form and the cranial and dorsal shields of Arthrodires indicated 
by Cope and the’ reviewer a few years ago were based upon a miscon- 
ception of the septum dividing off the so-called ‘nuchal plate;” but 
in reality no homology exists between arrangement of cranial plates or 
the sensory canal system of this form and those of Arthrodires. No 
plates corresponding to the dorsal or ventral armoring of Coccosteus, etc., 
are known, nor is there any evidence of a lower jaw, of paired fins, neural 
or haemal arches, nor any form of dental plates attached to the roof of 
the mouth. Finally, the bone-structure is perceptibly different from 
that of typical Arthrodires, and the under side of the head is unparal- 
leled in the latter group. This form is certainly worthy of careful 
reinvestigation. 
The whole matter of Dr. Dean’s Anarthrodira, is, however, of sub- 
ordinate importance as compared with his main theme, which is 
admirably treated ; and palaeontologists will be sure to appreciate his 
clear exposition of the same, supplemented as it is by a complete bibli- 
ography and expertly drawn figures. 
C. R. EASTMAN. 
Some High Levels in the Postglacial Development of the Finger Lakes 
of New York. By Tuomas L. Watson. With 30 figures 
and 3 maps. The figures being mostly full page half-tones, 
maps, and diagrams. Appendix B. Report of the Director 
of the New York State Museum, 1899. 
Dr. Watson presents in a very clear and interesting manner the 
results of the earlier works of other investigators and of his own 
extended observations on the high level terraces and water marks in 
the Finger Lakes region. He finds that at the time of maximum 
advance of the “‘ice of the second glacial period” (by which he prob- 
ably means the early or late Wisconsin of some writers) the ice front 
extended to and beyond the present divide which separates the waters 
draining northward into the St. Lawrence and those of the Chemung- 
Susquehanna draining to the southward. The preglacial valleys now 
occupied by the Finger Lakes were entirely overridden by the ice but 
were not completely filled with the glacial débris, so that as the ice 
front began to retreat and had drawn back to a position north of the 
divide there was formed, in the valleys, numerous local glacial lakes 
which drained southward through several channel ways. These channel 
