40 JOHAN KIÆR. M.-N. Kl. 



Segments : One or two fragments of isolated thoracic segments have 

 been found together with cranidiums of this form; they presumably belong 

 to each other, although it is possible that the}' belong to Ellipsocephalus 

 Norderiskjöldi. which is found in the same bed, although somewhat less 

 frequently. One of the segments is shown in the textfigure 6. It is 

 broad, strongly built, with broad furrows on the pleura, and a short, broad, 

 receding pleural spine. 



Occurence: Common in loose pieces of calcareous sandstone beds, 

 which occur at the old cutting in the Hohnia shales at Tomten. They 

 undoubtedly come from the shales, but probably from a horizon that lies 

 above the real Hohnia shales. From the calcareous sandstone beds in the 

 gray shales at Evjeviken, we also succeeded in preparing a distinct cranidium 

 of this form. (PI. V, fig. lo.j 



This species is not found in the real Holmia shales, but on the other 

 hand is extremely common in and the most characteristic form of the 

 calcareous sandstone beds somewhat higher up. The latter might therefore 

 be called Strenuella limestone. 



Observations: Only cranidiums are known, and these without the 

 free cheeks. The species is easily distinguished from Strenuella primaeva 

 Brøg. by its comparatively short and broad glabella, which is markedly 

 rounded anteriorly, and is there often intersected by a foremost (4th) furrow, 

 furthermore by its short cervical ring, by its narrower fixed cheeks, and 

 by the different form of its frontal brim. 



h was probably first depicted by Li.nnarsson, fig. 2 of his Ellipso- 

 cephalus Nordenskjoldi. The fact is, the cranidium here depicted cannot 

 very well belong to this form, and this was noted by Wi.man, who had 

 studied the original specimen. (See page 38.) It agrees very well with the 

 Norwegian specimens as regards the characters and proportions of the 

 cranidium. However, a direct comparison with the original specimen is 

 desirable. Moberg ' described and depicted a closely related form from 

 Tornetræsk, under the name Ellipsocephalus Xordoiskjöldi Lnrs. Judging 

 from the figure it is scarcely possible that this cranidium can belong to 

 Linnarsson's species. It should preferably be regarded as belonging to a 

 Strenuella form, the latter being closeh' related to the one described here. 

 However, the breadth of the cranidium is much greater, and the length of 

 the glabella much greater in proportion to the length of the head. For 

 the present, therefore, these forms cannot be united. 



1 Bidrag til kännedomen om de Kambrisice lagren vid Torneträsk. 1908. 



