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 casts of the inner surface. The first 
glabellar lobes are strong and sub-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 palj)ebral sulcus. 
Thorax. Length to width as 1 to 1.5. 
Axis arched, widest at the fourth segment, tapering thence evenly to the 
pygidium. 
Pleurae 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 pleurae, the anterior limb 
low and becoming obsolete along the fulcrum; the posterior limb slightly 
beveled, and considerably produced at the extremities. 
Pygidium 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 pleurae each bear five annulations which are sulcate, the posterior 
limb in each becoming obsolete near the margin, white the anterior limbs 
are tiattened, thickened, slightly curved and produced beyond the margin 
