1895. ] NEW YORK ACADEMY OF SCIENCES. 115 
A dorsal valve, supposed to be of this species, is deep com- 
pared with the ventral: it shows the interior which has a semi- 
circular scar at the umbo caused by the cardinal muscle, and a 
broad, low, two-grooved median ridge, running two-thirds of the 
length of the valve. There is a partly flattened rim running 
around the inner edge of the valve,on TH - 
Sculpture. The surface of the aoe veal ¥e is ornamented 
with very fine concentric and radiating ridges. 
Size. Length of the ventral valve 8 mm.; width 54 mm.; the 
dorsal valve is 7 mm. long. 
Horizon and locality. Found in Assises 1 and 2; and the 
dorsal valve ascribed to this species is from Assise 3. 
This species appears to be near Walcott’s LZ. granvillensis, 
which it resembles in the sculpture and in its regular oval form. 
L. Dawsoni, of the Paradoxides beds has a similar form, but 
the striation is coarser in valves of the same size. 
OBOLUS Eichwald. 
BoTsFoRDIA, subgen. 
Trans. Roy. Soc..Can. vol. ix., sec. iv., p. 63. 
BorsroRDIA PULCHRA, PI. iii 
Can. Ree. Sci. Jan. 1889, p. 303. 
Trans. Roy. Soc. Can., vol. vii., sec. iv., p. 151, pl. viii., fig. 1, 
atom, 2,atol; vol. ix., p. 62. 
Trans. Roy. Soc. Can., vol. xi., sec. iv., p. 90, pl. xvi, fig. 7, @ 
to ¢. 
This fine species was found in the northern basin of Cambrian 
rocks in southern New Brunswick, and cannot be so exactly 
placed as those of Hanford Brook; in the northern basin we 
ean only thus far distinguish Assise 5 from those below, and B. 
pulchra occurs low down in the Assises 2 to 4. 
Locality. Caton’s Island, King’s county, N. B. 
The original description of this species was as follows: 
“General outline nearly orbicular; the valves gently, but 
rather flatly and evenly arched downward from the centre all 
around, except that the dorsal is flatter at the back than else- 
where, and the ventral valve runs out into a short, acuminate 
unbo. 
Dorsal valve somewhat wider than long; more strongly arched 
toward the front than elsewhere; Spmieer hat elevated at each 
end of the hinge line. 
