3 
(b) Imperfect jaws, with hyoid arch and part of the pectoral girdle 
(PI. I, Eig. 2). 
(c) Portion of head and dentition. 
( d ) Portions of jaws with teeth (PI. I, Eig. 3). 
(e) Group of teeth (PI. I, Eigs. 4, 5). 
(/) Fragment of abdominal region (PI. I, Eig. 0). 
(g) Imperfect pectoral fin (PI. J, Eig. 7), 
(h) Imperfect pair of pectoral fins (PI. I, Eig. 8). 
Sp. Char . — Length of head probably nearly equal to the maximum 
depth of the trunk, which is contained about six times in the total length of 
tho fish. Teeth relatively much smaller than in the type species; the principal 
cones of the dental crown round and smooth, with a long and slender, straight 
intermediate denticle. 
General Form. — As suggested by the d’splacement of the vertebral 
axis, the type specimen appears to bo slightly deepened by crushing in the 
anterior part of the abdominal region; but this fossil seems to justify tho 
statement of proportions given in the specific diagnosis. The fish must have 
been laterally compressed, and the caudal region is comparatively slender. 
As shown by No. c, the snout is bluntly rounded. 
Head and Dentition . — The cartilages of the head exhibit excessive 
calcification, as usual, in small tesserae, and portions of them are thus well 
preserved though crushed. In the type specimen they are unfortunately too 
much broken to display any outlines ; but parts of the jaws are seen in Nos. 
h, c. The mandible especially (PL I, Eig. 2, md.) is shown to be long and 
slender, without much deepening at the hinder end ; and the dentition (t.) 
cannot have extended backwards beyond its middle point. The teeth are 
always badly preserved — in section, in cast, or partially encrusted with 
mineral matter, — but it is clear that they were unusually small for 
Fleur acanthus. As shown in PI. I, Eig. 2 a, the dental arrangement is in 
numerous, very close transverse series, of which some comprise at least fourteen 
teeth, deeply overlapping in the ordinary manner. In this figure they arc 
displayed partly in section, partly as hollow moulds ; in specimen d, chiefly 
in section but partly from the outer face ; while in the fragment marked e, 
they are scattered and display various aspects, but are partly obscured by 
encrusting mineral matter. The expanded bases which are seen from beneath 
