DUTCH BORNEO-EXPEDITION. 115 



surface of the front, consequently slightly concave in the 

 middle, appears very finely wrinkled and granular, 

 when examined under a lens and by means of the latter 

 a still finer granulation is observed on the post- 

 orbital groove. The free border of the front, which, just 

 like the upper margin of the orbits, is smooth, is divided 

 by a moderately deep and broad median sinus into two 

 distinctly arcuate lobes, that pass with a regular 

 curve into the lateral margins of the front i.e. into the 

 upper margins of the orbits, so that it is somewhat diffi- 

 cult to measure exactly the breadth of the free border. It 

 appears, however, to measure about one third the width 

 of the cephalothorax. The lateral margins of the front 

 diverge moderately backward, so that the front is much 

 broader at its base than at its free border; measured in 

 the middle, the height of the front i. e. the distance be- 

 tween the epigastric lobes and the anterior margin, appears 

 to be one third the breadth of the latter. A distinct trans- 

 verse crest runs immediately behind and contiguous to the 

 free border of the front, though this crest extends not 

 along the whole breadth of the margin (Fig. 13*). 



The moderately sharp outer angles of the orbits reach a 

 little less forward than the front; the distance between 

 them is about as large as the cephalothorax is long. The 

 lateral margins of the cephalothorax are S-like arcuate, so 

 that the carapace is narrowest at the level of the posterior 

 boundary of the gastric region and the postero-lateral mar- 

 gins are somewhat concave (Fig. 13). One observes almost 

 along the whole extent of the lateral margins numerous, 

 partly interrupted , oblique raised lines ; they are rather 

 long, reaching nearly to the middle of the branchial regions. 

 The foremost of these lines that bounds anteriorly the 

 oblique anterior portion of the cervical groove, runs obliquely 

 towards the lateral margin of the cephalothorax and other 

 interrupted lines border that groove posteriorly ; between 

 the outer angles of the orbits and these foremost oblique 

 Hues the lateral margin of the cephalothorax is slightly 



Notes from the Leyden Museum, Vol. XXI. 



