THE FAUNA OF THE ST. JOHN GROUP. 99 
Anterior margin —The marginal fold is a half wider at the ends than in front of the 
glabella. The flat area still connects in front of the glabella, but has been reduced in width 
to one half of the breadth of the corresponding part of the marginal fold. 
Glabella.—There is a marked increase in the size of the dome, and the fourth furrow is 
at its normal position in the adult, viz., on a line with the front of the ocular lobe. The 
fourth furrow is now also more than half way from the front of the dome. 
Occipital Ring.—The elevated lobe has disappeared from the middle of the ring, and 
in place of the width being more than a third of the length it is now less. 
Sculpture.—So far as it is preserved does not differ from the 6.4 mm. size. 
19.9 MILLIMeTREs (Fig. 5).—At this stage of growth the furrows become heavier and 
the front of the glabella somewhat conical. 
Anterior margin.—The limbs of the flat area are now separated and the marginal fold 
meets the front of the glabella. 
Glabella—The dome is larger proportionately in both diameters than in the last des- 
cribed stage, but the position of the fourth furrow remains unchanged. The occipital ring 
becomes more tumid and increases in length. 
The posterior margin also gains in width and length. 
The sculpture is that of the mature form. 
35.3 MILLIMETRES—The gap between this size and the last gives room for considerable 
change of form. 
Anterior margin.—The mle is now more than twice as wide as the extremity as in front of 
the glabella. The glabella gains a little in volume, and the fourth furrow is now three-fifths 
from the front of the dome. The posterior margin continues to gain in width. The fixed 
cheek is narrow and the ocular lobe shorter. 
37.1 Minuimerres (Fig. 4)—In this, the largest individual of this variety obtained, 
which was sufficiently well preserved for comparison, but little change from the last form 
is observable, if the affects of pressure be allowed for. The continued diminution of the 
ocular lobe is, however, a decided feature, and there is also a slight enlargement of the 
dome. 
It will be observed that the development of this variety does not proceed pari passu 
with that of P. eteminicus. 
Locality —Portland, near St. John, in Division 1c. Has not been collected elsewhere. 
Name.—In allusion to the Souriquois tribe of Acadian aborigines. 
Var. BREVIATUS. 
This form is acommon one, and like the last differs from the type in its shorter glabella, 
and in having a wider and more elevated dome. The length of the buckler is about 
equal to the transverse measurement of the fixed cheek and the glabella at the first furrow. 
Anterior margin.—The extremities of the marginal fold are proportionately narrower 
and more convex than in the two preceding forms. 
Glabella.—The length from the first furrow is equal to the width, and this furrow is 
heavily impressed all across. The fourth furrow is more than three-fifths from the front of 
the dome. a 
