OXYCHODOXTIDiE. 
391 
1890. Glyptolcemus kinnairdi , R. H. Traquair, Proc. Roy. Soc. Edinb. 
vol. xvii. p. 389. 
Type. Pishes ; Museum of Practical Geology. 
A very slender species, attaining a maximum length of about 0*4. 
Head with opercular apparatus mo v e than twice as long as its 
maximum depth, comprised about five times in the total length. 
Parietal region long and narrow, exceeding the frontal region in 
length; jaws much elongated; principal jugular plates rapidly 
tapering and acuminate in front, three and a half times as long 
as their maximum breadth. Pelvic fins remote, arising midway 
between the pectorals and the extremity of the caudal. Scales 
relatively smaller than in G. minor , these and the head-bones orna¬ 
mented with sharper, more irregularly developed reticulating rugse 
than in the latter species. 
This is the type species of the so-called Glyptolcemus. 
Form. # Loo. Upper Old Red Sandstone : Eifeshire. (?) Upper 
Devonian : Belgium. 
26117 aU Head and imperfect trunk, ventral aspect, showing a 
fragment of the left pectoral fin ; Dura Den. The speci¬ 
men is associated with the anterior half of the head of 
another individual, and remains of Holoptychius. 
Purchased , 1851. 
P. 6285. Fragment of trunk ; Dura Den. 
Enniskillen Coll. 
lO'iM 4 *- 
Family ONYCHODONTID-F. ' ‘ 
Scales cycloidal, deeply overlapping. Head and opercular appa¬ 
ratus with well-developed membrane-bones. Dentary bone of 
mandible thin and deep, bearing a single close series of large conical 
teeth, flanked by an outer series of very minute teeth; an azygous 
scroll-like element occupying a groove in the dentaries at their 
symphysis. Teeth plicated only at the base, with a central cavity ; 
dentary teeth tipped only, presymphysial teeth completely enve¬ 
loped with enamel. 
The single known genus of this family, Onychodus , has hitherto 
been found only in a fragmentary condition. The form and pro¬ 
portions of the trunk and fins thus await discovery. 
