Review of Recent Geological Literature. 149 
it is found attached was permanent, not temporary. 3. That the Platy- 
ceras attached to the body of a crinoid fed upon excrementitious matter. 
One of the new facts, and one of great interest, developed by the obser- 
vations of Keyes, is that the anterior border of the aperture of an attached 
Platyceras retained constantly the same portion, and that as the aperture 
enlarged in the process of growth the posterior border was successively 
moved further and further back. Lines drawn on the vault of the crinoid 
indicating the outlines of the aperture of the commensal Platyceras at 
different stages of growth, are eccentric and all pass through the point 
which makes the anterior border. This anal aperture of the crinoid lines 
within the eccentric outlines and near the point is common to all. By 
carefully removing the Platyceras it is found in some instances that the 
size and position of the aperture of the moUusk at different stages of 
growth are indicated by more or less perfectly defined grooves on the 
ventral plates of the crinoid. The significance of the facts here stated is 
manifest, the mouth of the mollusk at all periods of growth was placed 
directly over the anal aperture of the host. There are no indications that 
the presence of Platyceras interfered in any way with the convenience or 
success 1 f the crinoid. 
The American Anthropologist, published at "Washington, born the same 
year and month as the Geologist, begins its second year vigorously. It 
includes, but is not confined to, the transactions of the Anthropological 
Society of Washington, and aims to be a medium of communication be- 
tween students in all branches of anthropologic science. The managing 
editor is Mr. H. W. Henshaw, Washington. 
In tlie January number of the London Geological Magazine, Dr. Traquair 
discusses the two species Homosteus Asmuss, and Coccosteus Agassiz. 
The utter confusion in which the nomenclature of some of our fossil fishes 
is now placed is well shown in his introluctory remarks. He states that 
in 1840 Eichwald founded the genus Asterolepis for some Russian De- 
vonian fossils. Soon afterwards Agassiz named these same specimens 
Chelonichthys, This name he withdrew and adopted Asterolepis, erro- 
neously placing in this genus certain bones and plates from Dorpat of 
which he had received only casts. Hugh Miller following Agassiz con- 
sequently applied the name Asterolepis to the massive plates which he 
received from Robert Dick of Thurso, though these plates had no affinity 
to Eichwald's Asterolepis. The name Asterolepis has therefore two 
meanings, that of its author and that of Agassiz. 
In 1856 Asmuss described the Dorpat fossils and founded the two gen- 
era Homosteus and Heterosteus. "In the former of these is clearly to be 
recognized Hugh Miller's so-called 'Asterolepis' of Stromness " Pander 
subsequently changed Hugh Miller's name to Homosteus. This change 
has been adopted on the continent of Europe but not in Britain. 
Dr. Traquair goes on to show how Agassiz' work led Hugh Miller into 
other mistakes so that he attributed to his Asterolepis "the teeth of Den- 
drodus and the scales of OlyptoUpis. 
Pander classified Homosteus next to Coccosteus and rightly considered as 
its medio-dorsal plate the "hyoid" of Miller. A specimen found shortly 
