66 



gently curving inwards behind the axis and then shghtly outwards, and 

 terminating near the extremities of the inner pair of ribs ; three narrow- 

 rounded rings cross the anterior half of the axis. The anterior margin is 

 straight for a length of one-half the whole width, the outer angles broadly 

 rounded backwards to the tips of the first pair of ribs which are situated 

 on a line drawn across at half the length. The form of the first pair of 

 ribs is acutely sub-ovate, gently convex in the middle half of the lower 

 side, broadly convex on the outer side ; a deep groove along the middle. 

 A straight line drawn from the junction of one of these ribs to the outer 

 extremity, forms with the median line of the pygidium an angle of about 

 50*. The second pair are grooved along the middle, the grooves forming 

 with the median line an angle of about oO°, the half of the rib in front of 

 the groove sub-triangular, the posterior half with its anterior side (at the 

 groove) nearly straight, gently convex, the posterior side a nearly uniform 

 depressed arch. The last pair of ribs are nearly parallel with the median 

 line, irregularly triangular, and with a median groove which does not ex- 

 tend quite to the tips. From the axis a low convex ridge runs back to 

 the notch between the last pair of ribs. 



As the specimen is partly imbedded in the matrix the margin cannot 

 be entirely made out, but there are certainly two deep triangular notches 

 on each side and apparently a central notch as deep as the others but not 

 so wide in the median line. The whole surface is covered with minute 

 rounded tubercles just visible to the naked eye ; a few larger ones scattered 

 here and there, some of them one-fourth of a line wide. Length 14 lines ; 

 greatest width, at the tips of the first pair of ribs 21 lines ; length and 

 width of the axis 41 lines. 



Associated with this specimen was found part of a head with a glabella 

 very convex in front and with similar surface characters. Only the anterior 

 part is preserved. There is a projecting flattish margin one line wide round 

 the front. East Point ; Div. 3, A. G. J. Richardson. 



Genus Bronteus, Goldfuss. 



B. INSULARIS, n. sp. — Pygidium gently convex, semi-oval ; width greater 

 than the length in the proportion of 5 to 4 ; axis obtusely conical or sub- 

 triangular about one-third the length, its apex moderately well defined ; a 

 single groove across at the anterior margin where the width is nearly twice 

 the length. There are sixteen radiating ribs, the anterior pair rather ob- 

 sure. The outline of the pygidium is uniformly curved all round and just 

 within the margin there is a slight concavity. The ribs become obscure on 

 reaching the edge. All of the axis behind the groove and the anterior 

 margin is smooth. Length 4 lines ; width 5 lines. South-west Point ; Div. 

 4, A. G. J. Richardson. 



