CRUSTACEA. 43 



Glabella elongate-sub-pentagonal; length and width equal, and nearly 

 equal to the length of the cephalon. Frontal lobe large, transversely sub- 

 elliptical in outline; the width equal to one-third that of the cephalon. 

 The first pair of transverse furrows is long, directed obliquely backward; 

 the second pair shorter and more transverse; the third pair still shorter and 

 transverse. All these glabellar furrows are deeply impressed at their 

 proximal extremities, as shown in easts of the inner surface. The first 

 glabellar lobes are strong and sab-triangular; the second and third lobes 

 shorter and more annular. Occipital furrow very narrow and sharply im- 

 pressed ; occipital ring strongly arched upon the axis, narrowing behind the 

 ocular nodes, and widening again to the genal spines. 



Eyes large, elevated, exceeding the height of the glabella. Visual surface 

 lunate, corneal lenses numerous, an adult example showing fifteen rows, 

 numbering diagonally from the lower posterior margin, and 206 lenses for 

 each eye. Palpebrum inconspicuous, scarcely overlapping the visual surface. 

 Palpebral lobe depressed, sloping evenly to the narrow palpebral sulcus. 



Thorax. Length to width as 1 to 1.5. 



Axis arched, widest at the fourth segment, tapering thence evenly to the 

 pygidium. 



Pleura flattened, gently deflected along the fulcrum. Segments narrow 

 upon the axis, with a slight double curvature, bending forward along the 

 axial margins and axial line; grooved upon the pleura?, the anterior limb 

 low and becoming obsolete along the fulcrum; the posterior limb slightly 

 beveled, and considerably produced at the extremities. 



Pvgidium sub-triangular, depressed-convex. 



Axis tapering with slightly incurved margins, and ending abruptly just 

 within the posterior border; bearing from ten to fourteen annulations in 

 well-preserved specimens. 



The pleura eacli bear five annulations which are sulcate, the posterior 

 limb in each becoming obsolete near the margin, while the anterior limbs 

 are flattened, thickened, slightly curved and produced beyond the margin 



