200 TRANSACTIONS OF THE [May 18, 
almost at the beginning of Cambrian time is a proof,if any were 
wanted, of the very early origin of the Crustacean stem; and 
the rarity of plates that are found in the Paradoxides beds are 
sufficient to show that we are as yet but very imperfectly ac- 
quainted with these ancient types of Cirripedes. 
Barrande found the triangular valves of Plumulites three- 
lobed, by zones diverging from the apex, each having its peculiar 
sculpture. In describing these valves we’propose to follow his 
nomenclature, the two slopes being designated respectively the 
convex and concave sides, and the third side (by which the valve 
was attached) the base. 
PLUMULITES MANUELENSIS, n. sp. (Plate XV. fig. 7.) 
A triangular plate with curved sides, one concave, the others 
convex, rather blunt at the apex, somewhat straight along the 
base. <A band different in elevation from the rest of the surface 
of the plate traverses it from apex to base and is nearest the 
concave side. There are about fourteen strongly marked trans- 
verse ridges traversing the plate, parallel to the base. 
Sculpture.—Fine striz (about four to a ridge) on the trans- 
verse ridges. 
Size.—Length, 4 mm.; width, 34 mm. 
Horizon and Locality.—Soft gray shales of Div. 1 d?, at 
Manual Brook, Conception Bay, Newfoundland. Scarce. 
This resembles in shape Barrande’s P. compar of the Ordovi- 
cian of Bohemia, but is straighter along the base and more 
strongly arcuate in outline above the base. 
tis with great hesitation we refer the following genus to the 
Cirripedes as possibly representing the terminal plate of some 
such form as Strobilepis, or anchylosed plates similar to the 
terminal pair in Lepidocoleus; but it seems as likely a relation 
as any other that has been suggested. 
STENOTHECA Salter. 
This genus was proposed by Mr. J. W. Salter (published by 
Dr. Henry Hicks, in 1872), to include a minute corrugated shell, 
found in the Menevian group in Wales. It was described as a 
“curved shell, a small wide form, with lines of growth strongly 
marked on its surface.” The only species figured is S. cornu- 
copia. ; 
The genus is represented in the St. John Group at one 
locality by numerous examples from the horizon 1d. in a fine, 
dark shale. The little cones of this genus are always flattened, 
inequilateral, and usually have a more or less rigid band along 
