328 
CROSS OPTERYGII. 
flanked on either side by a large bone, this series being 
supratemporal according to Traquair’s nomenclature 
(p. 319). A pair of large parietals occurs, with a small 
squamosal on each side adjoining its hinder half; and 
the frontals are relatively small, separated by suture, and 
meeting some polygonal bones in front, but exhibiting no 
mesial foramen. The bones apparently to be regarded as 
postfrontals are larger than the frontals and squamosals, 
and are separated from the latter by the articulation of a 
large cheek-plate with the parietals. On the lower aspect 
the right mandibular ramus exhibits infradentary bones ; 
Fig. 49. 
Holoptychius jiemingi, Ag.—Dorsal aspect of head, one-half nat. size. 
[No. 261176.] 
a slender median, internal bone seems to belong to the 
hyoid apparatus; and, in addition to portions of the 
principal jugular plates, a lateral series of jugulars is well 
preserved on half of the right side. Purchased, 1851. 
37301. Imperfect head and greater portion of trunk of an equally 
large fish; Dura Den. Purchased , 1863. 
