36 BULLETIN OF THK NATURAL HISTORY SOCIETY. 
ocular fillet is wider than in the common form, and is orna- 
mented with forking and inosculating raised lines running to- 
ward the anterior marginal furrow ; such lines also appear on 
the surface of the fixed cheek, radiating from its posterior 
inner corner. 
Size. Length of middle piece of the head-shield in the 
variety with wide anterior margin, 22 mm., in the other 20 
mm. : width at the front of the middle piece 24 mm., at the 
eyelobes 28 mm. Length of the movable cheek (including 
spine) 26 mm. : width at the eyelobe 4 mm., behind it 6 mm. 
Horizon and Locality. In sandy shales of the upper part 
of Assise 2 in Band l. of Division 1 of the St. John Group, 
at Hanford Brook. 
Protolenus paradoxoides * n. sp. 
Head shield elongate semicircular. 
Middle piece subquadrate. Front Margin strongly arched 
in front, arched upward at the contact with the glabella, so 
that there is a sharp ridge here in 
place of the usual furrow. Gla- 
bella nearly a half longer than 
wide, indented at the sides in 
front of the eyelobe. There are 
three pairs of furrows, inclined 
backward and a trace of a fourth 
(anterior)furrow, directed forward. 
Occipital ring rounded forward at 
the back, divided from the gla- 
bella by a distinct furrow, which 
is more deeply impressed in the 
outer third : there is an obscure 
tubercle at the centre of the ring. 
Fixed Cheeks , ovate, flat, of moderate width and having a 
pear shaped tubercle opposite the third (anterior) furrow ; 
this tubercle is oblique to the ocular fillet, which crosses it 
but is faintly marked. Ocular lobes, distinct, moderately 
arched, continuous to the posterior marginal furrow. 
The dorsal suture runs direct to the margin of the shield, 
both before and behind the eye. 
Protolenus paradoxoides. Mid- 
dle piece of the head-shield, and the 
movable cheek. Both of the nat- 
ural size. 
^Contracted for euphony from paradoxidoides. 
