*270 
BULLELIN OF THE NATURAL HISTORY SOCIETY. 
the Dictyonema Zone on McLeod Brook, by its fossils, show a close 
affiliation with the zone 3 c at St. John, many species being identical 
with those of Cape Breton. 
The zones of the Cambrian terrane where the fossils described in 
this article were found are the following : * 
Bretonian Division. 
Parabo- 
lina Zone. 
Peltura 
Zone. 
Dictyone- 
ma Zone. 
Linguella ( ? ) Escasoni 
X 
Lingulella concinna 
X 
Lincnila (?) lens 
X 
Acrotreta bisec ta 
X 
X 
Schizambon priscus 
Agnostus trisectus mut. ponepunctus. 
X 
X 
X 
X 
Ao-nostus trisectus, mut. germanus . . 
Sphjeroph thalmus Fletcheri 
Parabolina Dawsoni 
\ 
DESCRIPTION OF THE SPECIES. 
Lingulella ( 1 ) Escasoni, n. sp. PI. V., figs. 1 a-i. 
i • 
Corneous, but having a thin outer calcareous layer. The inside of 
the edges of the valves is flattened. 
Ventral valve ovate, pointed at the apex, somewhat elevated from 
the umbo, along the axial line. Interior . — Cardinal area short, trav- 
ersed by a depressed pedicle groove. The cavity within the umbo has 
impressions of two small, cardinal muscles, from which radiate two 
grooves, bordered outside by ridges that separate the lateral muscle 
scars from the visceral cavity. The print of the central muscle is oval 
oi- lenticular and transverse to the axis of the valve ; it is divided 
lengthwise, half way, by a septum ; the posterior half of the scar is 
again divided by a faint ridge at right angles to the septum named 
The “1” laterals are small triangular imprints in front of the outer 
part of the central muscles. In some valves the paired scars of the 
“k ” laterals at the middle of the central group are small, and behind 
them extending toward the umbo is a sharp furrow enclosed between 
narrow ridges ; in others they are wider and the ridges are not pre- 
served. The grooves of the lateral muscles are discernable near the 
hinge on each side ; the transmedian (“ i ”) being external and on the 
A table at the end of this article shows the relation of these zones to the Cambrian 
succession as a whole. 
