RAYMOND: NOTES ON THE ONTOGENY OF PARADOXIDES. 237 
mm. long, or 18 mm. longer than the cranidium of Dr. Matthew’s 
specimen of P. regina. ‘This, restored on the basis of the dimensions 
of the wide form, would exceed both in width and length the P. regina; 
but, unfortunately it appears to belong to the narrow type, and would 
therfore cover considerably less area than that species. 
PARADOXIDES HAYWARDI sp. nov. 
Plate, ie. 1,2; ¢. 
Paradoxides harlani Walcott, partim, Bull. 10, U. 8. geol. surv., 1884, pl. 8, 
figs, 1, la, 1d. 
Among the many cranidia which have been collected at the Hay- 
ward quarry at Braintree there are a number which at the anterior 
end differ markedly from Paradoxides harlani. Instead of having 
a flattened rimless brim, they have an elevated striated marginal rim 
separated from the glabella by a narrow furrow. Moreover, the out- 
line of the margin of the anterior end of the cranidium, instead of 
being a smooth curve as in P. harlani, is obtusely pointed, the two 
segments of the rim being straight and meeting at an angle of about 
150° in front of the axial line of the glabella. The glabella is convex, 
semicircular in front, widest opposite the anterior ends of the palpe- 
bral lobes. The dorsal furrows are strongly marked and come to- 
gether in front of the glabella. No specimen so far seen shows any 
traces of glabellar furrows No. 1, and No. 2 when present, are only 
slightly impressed and do not show at all in most specimens. No. 3 
are quite strong but usually do not meet at the centre, though in one 
or two specimens they appear to. No. 4 extend across the glabella. 
The occipital ring is wide and bears a small median tubercle. The 
eyes are of medium size for the genus. The palpebral lobe does not 
reach the occipital furrow behind, nor is it connected with the glabella 
at the front. 
_ No free cheek has been seen which can be assigned with certainty to 
this species. Free cheeks seem to be less common than any other 
parts of trilobites at the Braintree locality. 
One specimen in the collection shows a part of a thorax still 
connected with a cranidium, though the body is partially shoved 
under the head. Eleven segments are present. The axial lobe is 
about one third the total width, and the pleura are marked by wide 
grooves which cross them diagonally, the grooves extending out to 
