78 



JOHAN KIÆR. 



M.-N. Kl. 



spines. From the 12th segment they increase rapidly in size and at the 

 16 — 17 segment become very long and powerful. The spine on 17th 

 segment stretches far behind the pygidium and like the somewhat smaller 

 preceding spine has extended basis, and in its inner parts is distinguished 

 by a triangular section and flat underside. (See fig. 3, pi. XIII and text- 

 fig. 12.) The i8th segment is without spine. 



The pleurae have a large doublure, that stretces in to the beginning ot" 

 the oblique furrow and ends in an inwardly concave arc with a narrow 

 stripe further in along the posterior margin of the segment. (Fig. 2, pi. XIII). 



The pygidium is small, broadly rounded, without segmental division, 

 and with marked oblique margin in its posterior part. 



The Sculpture. The shell has a marked net sculpture that is spec- 

 ally marked at the middle part of the thoracic rings. In the long pleural 

 spines outwardly the net sculpture extends in a network of somewhat long, 

 and more irregular anastomosing meshes. (Fig. i — 2, pi. XI\'). The 

 doublure of the cranidium and the hypostome attachments have also marked 

 undulating lines. The upper side of the cranidium on the contrary has a 

 very fine network or rather a fine ingraved sculpture which is not always 

 apparent. 



Dimensions. Kjernlfia lata often attains a considerable size. In my 

 material there are cranidiums up to 62 mm. in length and about 120 mm. 

 broad, which would correspond to a length of the body of 150 — 160 mm. The 

 specimens to hand otherwise show great variations in size. We also found 

 a quite young cranidium 4 mm. in length, a neanic stage, the most impor- 

 tant peculiarities of this form, however, having already fully developed 

 (Fig. I, pi. IX). 



1 refer moreover to the following table. 



The above measurements exhibit great irregularities in some instances, 

 on account of pressure in the shales Thus for instance A. K. 2 is greatly 



