1090 General Notes. [ November, 
result in a paper on these rocks which is now in course of prepa- 
ration. 
Although these zones have been mentioned by three or four 
writers, Dr. Tornebohm, who first observed them in certain 
gabbros from Sweden (Neues Jahrbuch fiir Mineralogie, &c., 1877, 
p. 383), is, so far as I am aware, the only one who has described 
them. Owing to the kindness of that gentleman I have had an 
opportunity of examining thin sections of a number of these 
wedish rocks. The double zone is well seen in them, but is 
much smaller than in the Canadian rocks, and the minerals com- 
posing it accordingly more difficult to determine. Dr. Tornebohm, 
although unable from kis sections to determine the nature of the 
inner zone, rightly regarded the outer one as hornblende. 
The chief interest attached to these zones arises from the fact 
that, as Tornebohm remarks, they appear to have originated from 
a mutual reaction between the olivine and the plagioclase. An 
examination of the thin sections of the Saguenay rock impresses 
one strongly with the conviction that they have resulted from the 
action of the molten plagioclase magma on the olivine grains, 
which in eruptive rocks always separate out before the plagioclase, 
thus having an origin similar to the kelyphite zones about pyrope 
described by Schrauf, and somewhat analagous to the zones about 
olivine and hornblende in volcanic rocks, which have recently 
attracted so much attention. The subject is one of importance 
as indicative of the processes at work in the genesis of rocks, and 
also as throwing some light on the much discussed question of — 
the origin of these anorthosite rocks.—Frank D. Adams, Geological 
Survey of Canada. 
EocENE PADDLE-FISH AND GONORHYNCHID#.—The Polyodon- 
tide or paddle-fish are only known from the American and Chi- 
nese rivers, and no trace of them has been found hitherto in the 
records of earlier periods of time. It is therefore of much interest 
to zodlogy that I am able to announce the existence of remains of 
a species of this family in the Eocene Green River shales of Wyo- 
ming Territory. This determination is based on a skull, of which 
one side is fairly well preserved, of an individual of the size of a 
middle-aged specimen of the common paddle-fish (Polyodon folium). 
The long snout is somewhat damaged, but was less dilated than 
in that species, being intermediate in character between the snouts 
of the American and Chinese forms (Psephurus gladius). The 
stellate bones are smaller and more attenuated than in the F- 
_ folium, and the gape of the mouth is not quite so wide. , The 
 symphyseal bone, enclosing Meckel’s cartilage behind, is much 
smaller. There isa bone in contact with the front of the oper- 
culum below, which may be one of two or three elements, which 
pparently not present in Polyodon, at least not in that posi- 
reason I propose to distinguish th 
ic fish cenerically 
