A16 Miscellaneous Intelligence. 
scope body and consequently of the goniometer circle which is attached 
to the object-glass; the crystal and vernier move to eth 
Within the eye-glass in the focus of the eye-lens is stretched a fine 
thread, or a divided glass micrometer can be used instead ; the object 
of this is the same as that of the lines drawn on the brass plate to 
which the crystals are attached in the original instrument, viz., to brin 
_ aside of the crystal under examination into a certain fixed direction 
». The mode of manipulation is the same as with the instrument first 
: et ibed ; In this latter form however we have the advantage of seeing 
at the same moment the position of the crystal and its action on the 
black cro 
The Ho ca al experiments were made with a Grunow microscope, 
discovered a law respecting the rotation of the planets on their axes, 
which he thus states: The cube roots of the oo of the planets are 
as the square roots of their periods of rotation. 
The author gives no demonstration of - grounds of this principle. 
In the present state of uncertainty concerning the densities of many 
of the planets, it may not be practicable to bring the truth of the law 
to a satisfactory test 
5. Shark remains from the Coal Formation of. Iilinois, and Bones 
and Tracks from the Connecticut River Sandstone ; by Prof. Hitcucock, — 
(in a letter to Prof. = aer dated Amherst, 12th Oct. 1855,)—At the 
late meeting of the American Association for the Advancement of 
Science, I exhibited a verbal fine specimen of a part of the jaw of 
a shark, allied to the Pristis family, obtained from the Coal Formation 
in Ilinois. After giving the history of the specimen, I submitted it to 
Prof. Agassiz, who observed that it belonged not only to a new genus, 
buta new family of fossil fishes, and I have requested him to name and 
describe it. Its history, locality, &c., I hope to send for your next 
volume. 
Within the present oie I have obtained a portion of the bones of a 
vertebral animal from the Red Sandstone of Springfield, Massachusetts. 
The rock is the same, and its geological position essentially the same 
as that in East vile Ct., from which you obtained some years ago 
similar ones—the only other instance known to me. For these bones I 
am indebted to the Hberality of William Smith, Esq., their discoverer ; 
who has charge of some excavations going on at the United States 
Armory ; and also to General Whitney, co Sle ph of the Armory. 
The larger part of the bones were thrown away by the workmen before 
they were noticed by Mr. Smith; but I have ais hopes that our anato- 
mists may determine from those that remain, to ‘what class the animal 
belonged. 
Yesterday I procured a slab, weighing nearly a ton, from Roswell 
Field, Esq., of Gill, containing four gigantic a hag ase of a 
iped, yet accompanied by most distinct traces of a tail. It is certainly 
one of the most remarkable tracks which I have ever seen, and wi 
probably, (as well as the bones above described,) throw light on the 
character of the animals that lefi the footmarks of this valley ; I propose 
