128 



Contributions to Palaeontology. 



DIKELO CEPH ALUS OSCEOLA ( n. s.). 



PLATE V, FIG. 18; AND PLATE II, FIG. 49? 



Head small in the specimens observed, having a length of 

 less than half an inch. 



Glabella with the sides nearly parallel, slightly narrow- 

 ing anteriorly, truncate in front. Occipital furrow nar- 

 row and well defined : occipital ring of the same con- 

 vexity as the glabella, and of equal width throughout. 

 Posterior glabellar furrow sharply defined in the cast, 

 and extending in a backward curve entirely across and 

 terminating a little in advance of the centres of the 

 palpebral lobe : the second furrow slightly marked on 

 the sides of the glabella. Dorsal furrow narrow and 

 well defined in the posterior part, slightly marked in 

 front. 



Fixed cheeks narrow, expanding towards the eye: pal- 

 pebral lobe limited by a distinct groove, which, in its 

 posterior inward curve, extends to a point opposite the 

 extremity of the occipital ring. Frontal limb of mode- 

 rate width, extending in front of the glabella in a broad 

 depression, which is nearly flat in the bottom, and 

 thence rising abruptly in a narrow marginal rim. 

 This species has been observed in three imperfect specimens of 

 the head. It resembles in general features specimens of the three 

 preceding species (Z). pepinensis, D. spiniger, and D. misa) ; but is 

 distinguished from all of them by the wide depression in front of 

 the glabella, and the abruptly elevated narrow border. These 

 specimens have the characteristics of the Genus Dikelocephalus, 

 as shown in all the preceding species. It occurs in the sandstone 

 at Osceola mills, associated with IllyENURUS. 



A small glabella associated with this one does not show the second 

 pair of furrows : it is more sharply truncate, and a little wider in 

 front; the frontal limb is shorter; the depression anterior to the 

 glabella is narrower, and the marginal rim a little stronger and very 



