SIXTEENTH ORDINARY MEETING. 1a 
York, and Ohio. The specimen in question, J. sulcatus, is ten and 
a-half inches in length, about an inch wide, and two-thirds of an 
inch deep. Its original length, however, may have been fourteen 
or fifteen inches. It is grooved longitudinally upon one side, smooth 
and keeled on the other. 
Symmetrical spines like Plewracanthus were, doubtless, implanted 
in the flesh, in front of the dorsal fins ; but the asymmetrical forms 
were, in all probability, imbedded in the integuments, before the 
pectoral fins. 
Judging from pieces of shagreen found with the spines, and the 
total absence of traces of a long skeleton, we may fairly conclude 
that these were the defensive weapons of very large sharks, which 
must have been formidable indeed. 
Mr. Dale mentioned a spine somewhat similar, which he 
had found in marl, in New Jersey, and drew attention to the 
mode of attachment of the spines, by which they were held 
erect, 
Mr. Boyle having asked as to the traces of shagreen in the 
rocks at St. Mary’s, Mr. Lennox replied that they were found 
in patches, five or six inches square. 
Mr. Livingstone suggested a theory that the carboniferous 
had something to do with the destruction of these fish, and 
that coal was the result of solidification of coal oil. 
Mr. Macdougall, Mr. Notman, and Mr. Murray, made some 
remarks, and the President noted the great interest of a 
discovery of remains of sharks at so remote a period. 
SIXTEENTH ORDINARY MEETING. 
The Sixteenth Ordinary Meeting of the Session 1884-85, 
was held on Saturday, February 28th, 1885, the President in 
the Chair. 
The minutes of last meeting were read and confirmed. 
It was moved by Mr. Vandersmissen, seconded by Dr. 
Kennedy, and resolved,—“ That the following gentlemen be a 
