SEMIOX OTID^E. 
189 
A small species attaining a length of about 0*2. Form variable, 
but maximum depth of trunk usually less than its length (exclusive 
of the caudal fin) in the proportion of about 6 to 7, and equalling 
approximately three and a half times the depth of the caudal pedicle. 
Head with opercular apparatus occupying nearly one-quarter of the 
total length of the fish; the external bones almost smooth, with 
very few small sparse tubercles, and the operculum also exhibiting 
reticulated markings. Marginal teeth bicuspid and robust. Scales 
smooth, and the hinder border not serrated. 
The young of Dapedius orbis being as yet unknown, it still remains 
uncertain whether or not the small fishes described as D. dorsalis 
should be thus interpreted. 
Form. Sf Loo. Lower Lias : “ Gloucestershire ” and Leicestershire. 
P. 7421. Type specimen figured by Agassiz, loo. oil. pi. xxi. figs. 1, 2; 
said to have been “ found in limestone near Byrford, 
Gloucestershire.” Possibly the locality intended is Burford 
Signet, Oxfordshire, where the Lower Lias occurs. 
Old Collection. 
P. 467. Impression of fish imperfect dorsally, figured by Agassiz, 
loo. cit. pi. xxi. a. fig. 1; labelled “ Gloucester.” 
Egerton Coll. 
P. 1553, P. 3532. Typical specimen in counterpart, labelled by 
Agassiz, and showing bicuspid marginal teeth ; Barrow- 
on-Soar, Leicestershire. Egerton df EnnisJcillen Colls . 
P. 1552. A much fractured fish, the maximum depth of the trunk 
0077 and its length (without caudal fin) 0*088 • Barrow- 
on-Soar. Egerton Coll. 
P. 1552 a. A large specimen 0*2 in length, having the trunk as 
deep as long; Barrow-on-Soar. Tubercles occur on the 
cranial roof, and there are bicuspid teeth in the jaw. 
Egerton Coll. 
P. 3530 x, P. 3531. Comparatively deep-bodied fish, 0*13 in length. 
in counterpart; Barrow-on-Soar. One side of the speci¬ 
men is labelled “ Tetragonolepis monilifer, Agass.,” the 
other “ Tetragonolepis striolatus , Agass.,” both in Agassiz’ 
handwriting. EnnisJcillen Coll. 
P. 3530. Four specimens variously imperfect ; Barrow-on-Soar. 
EnnisJcillen Coll. 
