HOLURUS PARKI. 169 



Length 2| inches to about 5 inches; greatest depth of body contained about 3^ 

 times, and the length of the head a little over 4 times in the total. 



Of the cranial roof-bones, the parietals, squamosals, and frontals may be readily 

 identified, and these are ornamented externally by sharp and delicate tubercles, which 

 sometimes assume an elongated contour. The suspensorium is oblique, the opercular 

 bones seem rather small, and, from defective preservation, their external ornament is not 

 well shown, though on the operculum a few raised striae similar to those on the other 

 head-plates may be observed. The maxilla has its upper margin as usual cut away in 

 front for the orbit; its broad postorbital portion is ornamented with delicate ridges 

 running parallel with the posterior and superior margins. The mandible is of medium 

 stoutness ; its outer surface shows traces of delicate striation. Only very few teeth can, 

 with considerable difficulty, be detected ; they are minute and cylindro-conical in shape. 



So far as exhibited, the bones of the shoulder-girdle are in every respect conformed 



Fig. 10. — Holurux Parli, Traquair, outline-restoration. Nat. size, br., branchiosfcegal vays; cl., clavicular arch; 

 mi/., mandible; mx., maxilla; op., operculum; or., orbit; pop., preoperculum ; s.op., suboperculum. 



according to the usual Pateoniscoid type, and are ornamented with ridges similar to 

 those of the head-bones. 



The body-scales (figs. 4, 5), rather small for the size of the fish, are rhomboidal in 

 form, and very ornately sculptured externally with minute and delicate, yet very 

 distinctly marked, ridges and furrows, whose general pattern on the flank-scales (fig. 4) 

 may be described as follows : Below a diagonal running between the antero-superior 

 and postero-inferior angles of the scale, these ridges have a nearly horizontal direction, 

 parallel with the lower margin, some of the lowest also turning up along the anterior 

 margin; while immediately above this diagonal some ridges are seen running downwards 

 and backwards parallel with it, while the uppermost pass backwards parallel with the 

 upper margin and then turn down parallel with the upper part of the posterior one ; a 

 few denticulations of the posterior margin are usually seen about the middle. Further 

 back the denticulations disappear, the pattern becomes less marked, the ridges tend to 

 fuse together, and the intervening furrows to degenerate into streaks and punctures, till 

 at last the minute lozenge-shaped scales on the sides of the powerful caudal body- 

 prolongation are nearly smooth. Along the middle line of the back, commencing near 



