CYBELE MICHELLI. 43 



Surface of glabella coarsely but sparingly tuberculated and with a line of three 

 equidistant specially conspicuous tubercles at front end just above marginal furrow, 

 the middle tubercle the smallest, and with the large tubercle on the anterior end 

 of each fixed cheek continuing the line laterally. Fixed cheeks nmch swollen, 

 rising suddenly and steeply from axial furrows, bearing three large tubercles in 

 front of eye and a large one at anterior end in angle between branches of axial 

 furrows ; posterior wing of fixed cheeks extended laterally, narrow from back to 

 front, with smaller and fewer tubercles. Pleuro-occipital ring narrow, rounded, 

 not tuberculate, marked off by deep furrow. Facial sutures with posterior 

 branch nearly parallel to posterior margin of cheek, cutting outer margin a short 

 distance in front of genal angle ; anterior branches running forwards from eyes 

 at about 120° to posterior branches and slightly converging as far as pits in axial 

 furrows, in front of which they curve sharply inwards, bending round and uniting 

 in front of glabella to form the rostral suture ; two short connecting sutures, 

 directed nearly at right angles to rostral suture and cutting anterior edge of head- 

 shield at about one-third width of glabella apart, with rostral shield between them. 



Free cheeks large, triangular, with inner swollen portion and steeply rising 

 from marginal furrow, coarsely tuberculate on upper anterior portion. Eyes 

 situated far back, opposite second lateral furrows of glabella and about one-fourth 

 the width of cheek from side of glabella, prominent, placed a little on outer 

 slope of subconical cheeks. Border of free cheeks broad, raised, somewhat 

 flattened, with inner row of 7 — 9 large equidistant tubercles and outer less regular 

 row of more numerous smaller ones ; anterior process embracing outer third of 

 front of glabella; marginal furrow rather weak. 



Thorax composed of thirteen segments ; axis convex, cylindrical, slowly 

 tapering, with swollen lateral lobes on each ring and deep pits in axial furrows 

 between them. Pleurae horizontal and straight as far out as fulcrum, then bent 

 gently downwards and backwards, composed of broad anterior depressed band 

 somewhat flattened and widening towards pleural extremity, narrower posterior 

 depressed band and strongly raised, rounded, slightly diagonal broad median ridge; 

 extremities of pleursE not preserved. Surface of thorax finely tuberculate, with 

 1 — 2 large isolated tubercles on median ridge of pleuree. 



Pygidium subquadrate, narrowing slightly posteriorly, with pleurae of lateral 

 lobes ending in short free points at same level along straight posterior margin. 

 Axis about one-third the width of pygidium, broad, subcylindrical, very slightly 

 tapering, composed of four rings at anterior end corresponding to the four pleuras, 

 followed by 10 — 1 2 rather narrower rings, all incomplete in middle ; short pointed 

 piece behind end of axis separating extremities of fourth pair of pleura. Pleurae four 

 in number on each side corresponding to anterior axial rings, lying in nearly same 

 plane and successively less strongly arched outwards, the fourth pair nearly straight 

 and lying closely pressed against sides of axis ; each pleura with diagonal furrow, less 



