SI REN OID El, 
42403. Upper aspect of head, much crushed and broken; Kil- 
minster, near Wick, Caithness. Peach Coll. 
P. 755. Large abraded cranial buckler, upper aspect, and two smaller 
imperfect examples ; Orkney. Egerton Coll. 
P. 3373 a. Imperfect cranial buckler, upper aspect, showing con¬ 
centric structure of the dermal plates; Orkney. This is 
the type specimen of Polyphractus gylatycephalus, Agassiz, 
ojp. cit. (1S44) pi. xxvii. fig. 1. Enniskillen Coll. 
P. 546. Operculum figured as Poly phr actus plcitycephalus by Agassiz, 
ibid. pi. xxxi. fig. 5 ; Orkney. Egerton Coll. 
33166. Anterior portion of skull, showing palatine dental plates; 
Thurso. Purchased , 1857. 
42405. Right palatine tooth attached to supporting bone; Thurso. 
Peach Coll. 
42404. Mandible seen in horizontal section in hard rock; Kil- 
fiainster. Peach Coll. 
36007. Imperfect fish, 0-25 in length, with portions of the pectoral 
and median fins ; Tynet Burn, Banffshire. 
Purchased , 1861. 
43270. Similar specimen, somewhat smaller, displaying large por¬ 
tions of both pectoral fins ; Tynet Burn. Purchased, 1871. 
20686-87, 20689-90. Four specimens showing more or less of the 
trunk and median fins; Caithness. The fourth specimen 
exhibits the two dorsal fins and a portion of the caudal, 
well exposed, with the distally branching rays. 
Purchased , 1847. 
33149-52. Slab with portions of about six fishes, and four imperfect 
larger individuals ; Thurso. Purchased , 1857. 
33172. Remains of anterior half of fish; Holburn Head, Thurso. 
Purchased, 1857. 
42480. Nearly complete small fish ; Banniskirk, Caithness. 
Peach Coll. 
P. 618. Small fish showing median and paired fins, figured in Mur¬ 
chison’s 4 Siluria,’ ed. 3, p. 287, fig. 71, and by Huxley, 
loc. cit. 1861, the figure being reproduced in the accom¬ 
panying woodcut (fig. 38); Banniskirk. Egerton Coll. 
