60 



[Assembly 



Fig. 1. Olenus thompsoni. 



OlENUS VERMONT ana ( II. S.). 



General form elongate : the posterior extremity 

 obtuse. Head semioval, twice as wide as long, 

 the posterior angles produced in short acute spines. 

 Eyes narrow elongate ; the space from the centre 

 of the head to the outer margin of the eye much 

 greater than the cheek, and the distance from the 

 anterior angle of the eye to the frontal margin 

 less than the length of the eye. Glabella lobed : 

 Fig. 2. Oluntjs vermontana. hypostoma broad oval. 



Thorax imperfect, preserving six articulations and part of the seventh ; 

 the middle lobe wider than the lateral ones. The third articulation is 

 much broader towards and at its lateral margin, and is prolonged ob- 

 liquely downwards in a sharp spine, which reaches below the seventh 

 articulation : the lateral extremities of the other articulations produced 

 in short acute gpiues. 



