﻿HOLOPTYCHIID^. 329 



26120 a. Portion of trunk of a somewhat smaller fish, displaying 

 the scales of the ventral aspect ; Dura Den. Four of 

 these scales are shown, of the natural size, in PI. XI. 

 figs. 1 a-d, the first two being taken from the abdominal 

 region, the third and fourth from the caudal region. The 

 two latter, it will be observed, are more delicate than the 

 former, and exhibit the anterior radiating rows of tubercles 

 usually regarded as characteristic of ' Glyptolepis.' 



Purchased, 1851. 



26120 b. Slab with remains of about nine individuals, smaller than 

 the foregoing ; Dura Den. The fins are almost entirely 

 wanting, and there are only fragments of the head and 

 branchiostegal apparatus ; but the scales are well pre- 

 served and sometimes, in the anterior abdominal region, 

 exhibit the partial subdivision of the superficial ridges. 



Purchased, 1851. 



26120 c. Group of typical scales and fragments ; Dura Den. 



Purchased, 1851. 



P. 2077-a. Imperfect fish showing portions of head and trunk, and 

 a small slab with remains of about four individuals; 

 Dura Den. Egerton Coll. 



P. 3277-8. Two small slabs with imperfect remains of individuals 

 showing the ventral aspect, associated with fragments of 

 Phaneropleuron ; Dura Den. The first specimen exhibits 

 the pair of jugular plates, well preserved but accompanied 

 by no anterior median plate. Enniskillen Coll. 



P. 3280-1. Two slabs, the first with remains of three individuals of 

 moderate size, the second exhibiting portions of several 

 small fishes with fragments of fins ; Dura Den. 



Enniskillen Coll. 



P. 3282. Imperfect fish of moderate size, exhibiting portions of the 

 head, left pectoral fin, and the ventral scales ; Dura Den. 



EnnisTcillen Coll, 



26119. Type specimen of Holoptychius andersoni, Agassiz, doubtless 

 to be regarded as a young individual of H. flemingi; 

 Dura Den. The fossil is completely detached from the 

 matrix and much crushed from above downwards. The 

 dorsal aspect, figured by Agassiz, exhibits several of the 

 bones of the head arranged as in No. 26117 h ; but most 

 of the sutures are omitted in Dinkel's drawing. The 



