1916. No. 10. 



THE LOWER CAMBRIAN HOLMIA FAUNA, 



61 



lobes. The 2nd lobe is broad or even broader than the frontal lobes. It 

 is narrow, extends somewhat outwardly and on both sides is markedlv 

 geniculated. The 3rd lobe is broader than the 2nd, does not extend as 

 far out to the sides, and is pointed in its outer part. The 4th lobe is some- 

 what broader than the preceding ones, is less marked and rather steeplv 

 cut oft' outwardly. The 5th lobe — or the occipital segment — is almost 

 of the same breadth as the preceding ones, and is divided across by two 

 faint cross furrows that extend inwards from the dorsal furrow. It is armed 



Fig. 10. Building of the cranidiutn of Holmia Kjeriilfi Lnrs.. Somewhat in 



outline. Nat. size, a From the side. h. From in front, c. From behind, ä. 



From the under side. 



with a somewhat strong, deflected spine. The furrows that border these 

 lobes are deepest at their outer parts, and then appear to run across the 

 glabella. However, this depends upon the state of preservation; in well 

 preserved specimens they are extremely faint in the middle or even vanish 

 altogether. iSee fig. i. pi, VII 1. 



The Eyes are long and greatly arched; they commence at the same 

 height as the furrow between the ist and 2nd lobes, and extend back- 

 wards to the hindmost furrow. The optic membrane has almost always 

 disappeared, and the palpebral lobe is pressed down so that only a cres- 

 cent-shaped fissure remains. The eye itself, which was found in an excel- 

 lent state of preservation in two specimens, is quite low, and especially in 

 front narrows somewhat. (PI. VII, fig.s i — 3, text-fig. 10). It will be described 

 in greater detail subsequentlv. 



The Palpebral Lobes are rising towards the inner edge of the eye 

 but as a rule they are pressed down with the eye. In general a deep 

 furrow divides the palpebral lobe into an inner and an outer part; this 

 furrow runs along the front edge of the eye in the shape of an arch. The 



