298 
ARTIIRODIRA. 
38032 a. Portion of shield ; Heightington. Purchased , 1864. 
38032 b. Pragment with impression of tubercular ornament, 
exhibiting a tendency towards a concentric arrangement, 
and partly shown, of the natural size, in PI. VIII. fig. 7 ; 
Heightington. Purchased , 1864. 
37388 b. Imperfect flat plate, shown, of the natural size, in PI. VIII. 
fig. 8, and probably referable to the ventral armature of 
the trunk. Two of the four borders of the plate are 
apparently thicker than the others, are unbroken, and 
meet in a wide, rounded angle ; the tubercles are arranged 
in series concentric with these borders for some distance 
towards the centre of the plate, and gradually decrease in 
size until they become very small inwards. 
37388 c, 38032 C. Two nearly similar plates ; Heightington. 
Purchased , 1864. 
The following is a bilaterally-symmetrical ridge-plate, resembling 
that assigned to Zenaspis by Lankester, op. cit. pi. viii. figs. 2, 3 ; 
reasoning from the shape of the plate and the character of its orna¬ 
mentation, it may well be the dorsal shield of the trunk of Phlyc- 
tcenaspis anglica. 
38032 d. Internal cast of shield, with fragments of the bony tissue 
and its characteristic ornamentation preserved at what 
appears to be the hinder extremity ; Heightington. There 
are remains of an inner longitudinal keel, apparently re¬ 
sembling that of the median dorsal plate in Coccosteus. 
Purchased , 1864. 
The following specimens from the Lower Old Red Sandstone of 
Herefordshire may also pertain to Coccosteidse related to Phlgctcen- 
aspis , but their determination is quite uncertain :— 
,A1‘ 
P. 194.^ An oval plate, exposed from the inner aspect, truncated 
at one extremity, measuring 0-095 in length and 0-063 
in maximum breadth. There is a longitudinal median 
elevation in one half of the shield, and an impression 
of part of the outer aspect shows that it was coarsely 
tuberculated. Weaver-Jones Coll. 
P, 5274. Two small ridge-scutes, probably of an imbricating series, 
and externally ornamented with large tubercles ; Cradley. 
j One specimen is shown, of the natural size, in PL VIII. 
fig. 9. Purchased , 1885. 
