Notes on Fossils of Utica Formation. 105 
specimen and the Siphonotreta micula described by Prof. 
McCoy ' from the Llandeilo :ocks of Great Britain, and 
which he himself recognized. afterwards in rocks of similar 
age in Australia. Dr. Bigsby, in his ‘ Thesaurus Siluri- 
cus,” states that S. micula, McCoy, occurs in Meath, 
Ireland, England and S. W. Scotland, at Glenkiln, Dum- 
frieshire, and in several localities in Wales. The Murray 
Bay specimen differs from S. micula in having the con- 
centric lines of growth or strie more distant, there 
being only twelve in the space of one millimetre, whilst 
there are are said to seventeen in the same space in the 
latter. The spines, again, are comparatively longer in the 
Murray Bay form than in S. Scotica, but much more numer- 
ous than in S. micula. They are exceedingly slender and 
smooth. The specific relations of this form require better 
specimens before definite conclusions are arrived at. 
5. LepraNna sERICEA, Sowerby.—Only a fragment of what 
uppears to be this ubiquitous and common species oc- 
curs in the collection. 
6. ORTHIS TESTUDINARIA, Dalman, var.—This species of 
Orthis resembles one which is found in tolerable abun- 
dance in the limestones at the foot of the Montmorency 
Fails, near Quebec. It is here provisionally referred as 
a variety of Orthis testudinaria, though there is good 
reason for a different specific dvsignation. The coste, 
especially about the beak and along the anterior 
margin, differ considerably as to their arrangement and 
distribution. 
CEPHALOPODA. 
7. TROCHOLITES AMMONIUS, Conrad.—The mode of occur- 
rence, preservation and characters of the specimen 
referred to this species agree perfectly with the numer- 
ous individuals occurring in the Utica shales of Whitby, 
Ottawa and Collingwood. 
' British Palzozoic Fossils, pp. 188 and 189; Pl. 1 H. fig. 8. 
