852 TRILOBITES FROM N.S.W. 



border of the free cheeks of the latter clearly separates the one 

 from the other. 



From Acidaspis vesiculosa Barr. the present species differs 

 in having the front margin of the cephalon almost smooth and 

 the anterior-lateral angles more acute. 



hoc. and horizon. — Minahan's Selection, Bowning Creek, Parish 

 of Bowning, County Harden, N.S.AV. Lower Trilobite Beds of 

 Bowning- Yass Series. Upper Silurian, probably the equivalent 

 of Barrande's etage E . 



Odontopleura hartleii, n.sp. 

 (Plate xlvii., figs. 4-8.) 



Whole form unknown. 



Cephalon. — Subsemicircular, only very moderately convex and 

 appears to have been finely granulated. Greatest length and 

 width 6.25 and 15.6 mm. respectively, or approximately two 

 and a half times as broad as long. Glabella — medial portion 

 moderately convex, finely granulate, antero-lateral angles ex- 

 panded and prominent; two pairs of lateral glabellar furrows 

 present; they are deep and circumscribe the glabellar lobes, the 

 first pair of which is subquadrate, and the second or basal pair 

 is much the larger. Neck furrow medially exceedingly faint, 

 but narrow and deep behind the basal lobes. Neck ring wide, 

 gently arched; bases tuberculate, and join directly with the genal 

 lobes thus interrupting the axial furrows, and the lateral ex- 

 tensions of the neck furrow. Fixed cheeks small, the lobes only 

 moderately tumid and small ; eye lines or ridges mildly developed 

 and surmounted by a row of small tubercles. Triangular areas 

 of moderate size, slightly concave. Wings long and very nar- 

 row, traversed by very narrow and almost invisible furrows; 

 along the anterior and posterior margins are rows of very fine 

 granules. Front border linear and very finely dentate. Free 

 cheeks large, fairly tumid, spaces between the eyes and lateral 

 furrows bear five or six irregular rows of tubercles of varying 

 sizes; lateral furrows shallow, borders strongly thickened and 

 bear fourteen or more spines. Genal spines strong, long and 

 slightly falcate. Eyes small, situated opposite the neck furrows. 



Thorax not known. 



Pygidium. — Greatest length to width approximately 2:5. 

 surface finely granulated, articulating face straight to near the 



