40 JOHAN KI^R. [sec. ARCT. EXP. FRAB 



triangular facet by which it overlapped the posterior ventro lateral plate. 

 ^Vithin the brachial joint of the arm we see the inner cross rib. In 

 front of this the plate is incomplete and cannot be exactly limited. 

 The proximal part of the arm, which is also seen from below, is well 

 preserved in the outer part; we here see the sculpture, the strong- 

 marginal spines and the suture between the external marginal plate and 

 the ventral anconeal plate. 



The sculpture consists of a network of fine ribs without nodes. 



The anterior ventro lateral plate gives the impression of being 

 .short and broad. The following dimensions may be determined on this 

 specimen: — 



a. Length of anterior ventro lateral plate from the back point to the 

 cross rib within the brachial joint . . 19 mm. 



b. Length of the proximal part of the arm .... . . 33 mm. 



c. Breadth of the proximale part of the arm . . .8 mm. 



2. Another specimen (S. L 103), which is shown in PI. VII, figs 

 -—3, gives the interior of a plate; I consider this to be an anterior 

 dorso-lateral plate. In front it is somewhat imperfect, but iti original 

 borders may be seen, especially on the left and posterior sides. Here 

 we observe fine lines of growth parallel to the margin. Behind we 

 see a long facet with which this plate overlapped the posterior dorso 

 lateral plate. The plate is short and broad, and gives the following 

 dimensions: — 



a. Length . ... ... . .... 17 mm. 



b. Breadth in the centre . 19 mm. 



c. Breadth farther forward . 20 mm. 



3. PI. Vll, figs 4—.") shows the outer impression of a third plate 

 |S I. 100) which I regard as a fragment of a posterior dorso lateral 

 plate. It slunvs a triangular facet before the anterior dorso lateral plate. 

 The sculpture is clearly visible and consists of a netwoi'k of fine ribs 

 without nodes. 



In addition to the remains of plate.s from Galge Valley described 

 liere in greater detail, there are also not inffequentiv quite small frag- 

 ments of plates with similar sculpture amongst the material from Skrap 

 Valley. It is extremely probable that these remains also belong to the 

 same form. The majority are too small and incomplete for us to 

 determine to which plates they belong. Some can howevei- be identified 

 as fragments of arm plates. The most complete, (S. I. 24) is depicted 

 ill PI. VII, fig. 6. I regard Ibis specimen to be a dorsal articular plate. 



