BY R. ETHERIDGE, JUNE., AND JOHX MITCHELL. 703 



segments are present, they are so much reduced in size as to 

 indicate a transition towards 0. Rattei. 



Named in honour of the late Mr. Felix Ratte, Mineralogist to 

 the Australian Museum, Sydney. 



Loc. and Horizon. — Bowning Village, Co. Harden, Middle 

 and Upper Trilol:)ite Beds— Bowning Series { = Hume Beds, Jenkinfi, 

 and Yass BeJs, David)—? Wenlock. C'o^/. —Mitchell. 



Odoxtopleura parvissima, sp.nov. 



(PI. L., figs. 4-6; PL LiL, fig. 8.) 



Acidaspis near A. Dormitzeri, Ratte (non Corda), Proc. Linn. 

 Soc. N.S. Wales, 1887, ii. (2), Pt. 2, p. 96, t. 2, f. 1, 1 bis. 



Sp. Char. — Body. — Suboblong-oval. Cephalic shield or cephalou. 

 — Subquadrate, twice as wide as long, tumid and strongly 

 tubercled throughout. Glabella quadrate, half as long as the thorax, 

 or including the lieck ring its length equals the width between the 

 eyes; central lobe narrow, intensely arched transversely, moder- 

 ately so fore and aft, extending to the front or limb, which is 

 straight and appears under a strong lens to be delicately 

 dentate ; the lateral lobes mere tubercles ; lateral and false 

 furrows distinct; axial furrows indistinct. Fixed cheeks very 

 small and tumid; genal lobes very small (practically narrow bands 

 each bearing a row of tubercles) ; genal or palpebral furrows 

 moderately distinct; ocular ridges distinct anteriorly and tubercled. 

 E3''es very small and prominent. Free cheeks proportionately 

 large, tumid, outer borders thickened, narrow, and each bearing ten 

 short acicular horizontal spines, and on the upper surface a row 

 of prominent tubercles; genal angles produced into long, slender 

 and subfalcate spines. Facial sutures distinct, anteriorly gently 

 curving towards the axis and passing out at the front angles of the 

 central lobe; posteriorly- are parallel with the edges of the lateral 

 extensions of tlie fixed cheeks, and pass out at the genal angles. 

 Neck furrow distinct, narrow, lateral extensions faint. Neck 

 ring intensely arched, lateral nodules small, but distinct, 

 tubercled, but no prominent central tubercle. 



