1916. No. 10. THE LOWER CAMBRIAN HOLMiA FAUNA. 7I 



and the unusualh" broad outer cheeks. These peculiarities appear so promi- 

 nently that the specimen cannot be identified with any previously known 

 species. Unfortunately we do not yet know the nature of the other struc- 

 tural features of the bodv. 



Kjerulßa nov. gen. 



The cranidium and the entire shape of the body are very broad. The 

 glabella is of somewhat uniform breadth and narrows anteriorly. The first 

 lobe is pointed almost pear-shaped, the second is narrow and slighüy bent 

 outwards. The eyes are large, with markedly prominent palpebral lobes, 

 that as usual run into the lateral folds of the ist lobe of the glabella. 

 The posterior margin of the cranidium extends straight out to the broad, 

 comparatively short but sharply pointed genal spines. There are no 

 distinct intergenal spines, but faint intergenal angles. The cranidium is 

 surrounded by a very broad and slightly arched brim which corre- 

 sponds to the somewhat broad hypostome attachments by which the broad 

 hypostome is firmly attached. There are i8(?i thoracic segments which are 

 somewhat uniformly developed; the\- have broad, in the outer parts cur\-ed 

 falcate pleurae. The posterior ones cur\ e markedly backwards. The occi- 

 pital segment and the first thoracic segmens are provided with quite short 

 genal spines which do not markedh* increase in size until the hindmost 

 ones. The}- increase now rapidly in size and become especially powerful and 

 long at the i6th and 17th segment. The i8th segment is without spine. 

 The pvgidium is small, patch shaped, with a round outline, without 

 marked axis. 



Genotype: Kjentlfia lata nov. sp. 



This form, which is quite common at Tømten, was found there formerly 

 but was regarded as old large specimens of Holmia Kjendfi Lnrs. My 

 extensive material shows however that most characters are fully devel- 

 oped even in young specimens, of which several were found in the present 

 instance. (Pl.IX.i 



It evidently belongs to a quite different type, which cannot be referred 

 to the Holmia genus. I need only here refer to the diagnosis given above. 



Nor does it fit in with any of the other known Mesonacidae genera, 

 although in certain features it shows agreement with several of them, e.g. 

 Ellipiocephala, li'amieria and Callavia, which all have a similarl}- broad 

 and short thorax, with broad genal spines, falcate pleurae and a small, 

 patch-shaped pygidium. 



