10 JOHAN KLER. [SEC. ARCT. EXP. FRAM 



The proportion mentioned above would in that case decrease to 

 about 1.2. 



The greatest breadth appears to be almost exactly at the middle, 

 by the supraorbital commissure. The outline is oval, but in the front 

 (at the snout) it is narrower. The foremost portion of the cranial shield, 

 between the orbits and forwards, is flat; farther back the head is 

 rather markedly arched, and as is usual in this genus, there is a 

 slightly rounded protuberance behind the eyes. The sides of the head 

 behind the eyes are somewhat steep. 



Fig. 1. Three cross-sections of Macropetalichthys Scheii new species. Uppermost, 

 near the supra-orbital commissure. The centre figure at the point where the post- 

 orbital canal branches off in the medial bone. Below, at the posterior end of the 

 postorbital canal. Natural size. 



Sculpture. This is only visible on a small part within the right 

 orbit. At this spot the surface shows fine, slight crenulated tubercles, 

 which behind appear to have a tendency to run together into longi- 

 tudinal ridges. 



Structure of the cranial bones. Plate I, fig. 5, shows a 

 microscopic section through the right side of the cranial shield, behind 

 the supraorbital and infraorbital canals. The portion of the section 

 which appears greatly enlarged in fig. 6, is from the thickest part, inside 

 the postorbital canal. 



The structure clearly shows agreement with that of Coccosteus deci- 

 piens. The vascular canal system, however, is wider and has thinner 

 walls than is the case with the latter; a comparatively compact base- 

 ment layer also appears to be lacking. The bone-cells are small, often 

 round, as in the case of Coccosteus. 



Characters of cranial shield. The separate bones of 

 the cranial shield cannot be distinguished. They must be assumed to 



