144 TRANSACTIONS OF THE [MAR. 14, 
graphic development since the Cretaceous period of the country 
lying west from Chattanooga across the Sequatchie valley to the 
Mississippi river. The Cretaceous and Tertiary peneplains were 
illustrated by means of maps and sections, and the present de- 
velopment of the drainage system was traced out. President 
Stevenson, in discussing the subject, described his own observa- 
tions in West Virginia and western Pennsylvania. 
The Section then proceeded to the election of officers for the 
ensuing year: Professor J. J. Stevenson was chosen Chairman 
and Professor J. F. Kemp, Secretary. 
The Academy then adjourned. 
J. F. Kemp, Secretary. 
ON THE OCCURRENCE OF CIRRIPEDES IN THE 
CAMBRIAN ROCKS OF NORTH AMERICA. 
By G. F. MatrHew. 
In a revision of material collected from the Cambrian rocks 
of Canada and Newfoundland, the author has investigated some 
peculiar calcareous plates which occur at several horizons; as a 
result he has come to the conclusion that these are the scattered 
tegumentary plates of animals related to the barnacles. 
These plates are of various forms, but the majority agree in 
having a carina, usually nearer one side than the other. From 
the fact that the plates are depressed on one side of the carina 
and elevated on the other, it may be inferred that they are parts 
of imbricated series. Occasionally plates are found which are 
convex on both sides of the carina; such plates are more sym- 
metrical than the others. 
The above plates differ from Plumulites of Barrande in being 
comparatively smooth, the only sculpturing of the surface being 
delicate growth lines near the lower margin. 
Beside the above plates there are other plates marked by 
sharply raised, closely set ridges, parallel to the lower margin. 
Some of these agree perfectly with Barrande’s Plumulites, others 
are more arcuate, others still have more distant growth ridges, 
etc. 
Such is the variety of form in the smooth plates that it is 
highly probable that more than one species (perhaps more than 
one genus) is represented. But as the plates found were de- 
