316 THE SILURIAN TRILOBITES OF NEW SOUTH WALES, 



Loc. and Horizon. — Bowning Creek, Bowning, Co. Harden 

 (Coll. Mitchell) ; Middle and Upper Trilobite Beds of the Bowning 

 Series — Upper Silurian (1 Wenlock). 



Proetus Rattei, sp.nov. (PI. xxv., figs. 2, 2a-d). 



Proetus ascanius, Ratte (non Barrande), Proc. Linn. Soc. N. S. 



Wales, I. (2), Pt. 4, p. 1066, t. 15, f. 1-4. 



Sp. Char. — Body oval and flattened. Cephalic shield large, 

 semicircular, and slightly convex ; limb wide, flattened, or slightly 

 concave, with anastomosing striae. Glabella short, square, and 

 somewhat trilobed by two shallow longitudinal furrows, extending 

 from the neck furrow to the front ; basal pair of lateral furrows 

 present, uniting the longitudinal furrows, and so dividing each 

 lateral lobe into two; neck furrow distinct, narrow; neck segment 

 wide, slightly convex about the middle ; axial furrows rather faint, 

 continuing round the front of the glabella; facial sutures ante- 

 riorly rather straight, and gently directed outwards to the margin, 

 behind they cut the posterior margin at a distance from the glabella 

 equal to that of one-third the width of the thoracic pleurae ; fixed 

 cheeks very small ; free cheeks large, very moderately convex ; 

 genal angles continued into stout spines, directed outwards slightly 

 from the thorax, and extending as far as the fourth segment of the 

 latter. Thorax of eight segments, the axis and pleurae at the 

 anterior end being about equal in width, but posteriorly the latter 

 are much the wider ; lateral margins straight ; axis flat or very 

 slightly arched ; pleurae flat and bent backwards towards their 

 outer ends, terminating in rather claw-shaped spines, those of 

 the third pleurae apparently longer than the others. Pygidium 

 relatively large, about three-fourths as long as the head-shield, 

 subsemicircular ; axis conical, of eight rings, the terminal ones 

 very faint ; contracting rapidly to the margin of the limb, thence 

 continuing to the circumference as an acicular ridge, axial furrow 

 distinct ; pleurae eight, distinctly furrowed, the furrows extending 

 across the limb to the circumference ; limb wide, marked off by a 

 faint concentric depression, and faintly striated with concentric 

 wavy striae. 



