121 



flat, somewhat arched from the front backwards, less from side 

 to side. 



The front is broad and somewhat bent down, its breadth 

 is about V4 of the whole breadth of the carapace ; in the above 

 mentioned specimen it is thus 6 mm. broad. The whole breadth 

 of the anterior margin (22 mm.) is about V5 of the greatest 

 breadth of the carapace. The front is somewhat prominent, 

 projecting by about half its breadth beyond the anterior 

 margin. The front margin ends in four short spines, separated 

 by incurvations, they are about on the same plane, the inner- 

 most however are a little deeper than the outer ones because 

 the sides of the front rise a little in proportion to the middle 

 part. The outer spines are somewhat stronger than the inner 

 ones, and directed somewhat to the side, all four spines project 

 about equally. The distance between the two middle spines 

 is only half as great as between one of the middle spines 

 and one of the outer ones. After the outer spine comes a 

 little furrow, and at the same time the anterior margin bends 

 backwards, and forms a bowed incurvation the margin of which 

 turns somewhat upwards ; this incurvation is bordered by a 

 small slit which extends itself into a furrow. Then follows a 

 small slightly prominent part which is again bordered by a slit. 

 The margin now bends forward again, and ends in a strong 

 triangular spine where the anterior margin , and the anterio- 

 lateral margin meet. The margin from the front to this place 

 is the supraorbital margin which forms the border of the orbit 

 upwards; it is surmounted by a row of small tubercles. The 

 angle between the anterior margin , and the anterio-lateral 

 margin is about 120°. The anterio-lateral margin is slightly 

 convex, and has the same length (8 mm.) as the supraorbital 

 margin. It carries five strong spines, whereof the fifth and the 

 first are the strongest, while the second and the fourth are the 

 weakest, and lie on a somewhat lower level than the rest. The 

 four front spines are (in casts) flat, and directed more or less 



