﻿PALJEONTRCTD/TC. 



519 



P. 2026. Head, abdominal region, and some of the scales of the 

 caudal region, vertically crushed and showing the dorsal 

 aspect; Lyme Regis. The tubercular ornamentation of 

 the cranial roof and the anterior two-thirds of its pair 

 of longitudinal sensory canals are well exhibited; and 

 there are indications of a series of small ossifications in 

 the axial skeleton of the trunk — evidently the expanded 

 bases of the arches. Of the fins, only the right pectoral 

 and the dorsal are preserved. There is no median series 

 of enlarged dorsal ridge-scales ; but the squamation of 

 the anterior dorso-lateral region is well preserved, and 

 the ornamentation is distinctly exhibited. The ridges 

 upon these scales are extremely delicate and frequently 

 interrupted, appearing as series of elongated tubercles. 



Egerton Coll. 



39860. Imperfect fish, (>365 in length, ventro-lateral aspect, 

 showing all the fins except the dorsal, and confirming 

 many of the characters mentioned above ; Lyme Regis. 



Purchased, 1866. 



38734. Head and trunk of small fish, ventral aspect, imperfectly 

 preserved and wanting all the median fins. The pelvic 

 fins and one of the pectorals are shown. Purchased, 1865, 



P. 3509. Imperfectly preserved fish, wanting the extremities of the 

 head and tail ; Lyme Regis. This specimen is noticed by 

 Agassiz, and described by Egerton as the type of Thris- 

 sonotus colei. The fact, however, that the scales are com- 

 paratively smooth and exhibit concentric structural lines 

 is due to the preservation of the fossil in a hard nodule ; 

 while the supposed great relative length of the anal fin 

 seems to be partly a false appearance, caused to some 

 extent by the displacement of the scales and its hinder 

 fin-rays, and by the loss of the distal extremities of the 

 anterior rays at the margin of the nodule. Traces of the 

 dentition and the characteristic ornament of the jaws and 

 cranial roof are distinguishable. EnnisTcillen Coll. 



P. 874. Crushed remains of a large head. Egerton Cotl 



P. 3487 g. Caudal fin. EnnisTcillen Coll. 



