286 
ARTHRODIRA. 
(ii.) Caithness. 
43663. Imperfect remains of a very large individual, displaying the 
same aspect as the two last-mentioned specimens ; Hol- 
burn Head. Purchased, 1879. 
20346. Median dorsal plate and imperfectly preserved caudal region. 
Purchased, 1846. 
(iii.) Edderton, near Tain, Ross-shire. 
38727. Imperfect head, dorsal aspect, and several portions of plates 
of the trunk. Purchased, 1865. 
39898. Inferior aspect of imperfect cranial roof. Purchased , 1866. 
P. 635, P. 1171. Roof of skull, imperfect laterally; also the im¬ 
pression of a similar specimen associated with a mandibular 
ramus and portions of the plates of the trunk. 
Egerton Coll. 
P. 5600. Less imperfect example, with displaced maxillaries and 
premaxillaries, one of the latter apparently exhibiting the 
notch interpreted as nasal by Traquair. The specimen 
also exhibits one of the anterior dorso-lateral plates. 
Harford Coll. 
38728. Crushed median dorsal plate, associated with portions of 
other plates, fragments of the axial skeleton, and a small 
undetermined, almost reniform element, apparently un¬ 
ornamented. Purchased, 1865. 
41729. Imperfect median dorsal plate, probably uncrushed, asso¬ 
ciated with portions of other plates. In the median 
dorsal the rounded longitudinal keel only extends along 
the posterior two-thirds of the bone, the surface sloping 
downwards both in front and on each side of its com¬ 
mencement. Purchased, 1869. 
P. 695 a, P. 1171 a. Portions of the dorsal and ventral plates of the 
trunk, with the supporting bones of the dorsal fin and 
part of the axial skeleton, in counterpart. Remains of 
the pelvic elements are distinguishable, and in the ab¬ 
dominal region the small unornamented plate, figured 
below in Ho. 43617, is exhibited. Egerton Coll. 
P. 1171 b, P. 3220 a. Ventral plates of trunk, with remains of 
dorsal and lateral plates, in counterpart. 
Egerton 4' Enniskillen Colls. 
