Siluna7i.'\ PALAEONTOLOGY OF VICTORIA. ITrilobites. 



cheeks very tumid in an oblique line from the small eyes to the neck-seg'ment, which 

 is strongly marked and separated from base of glabella by a wide sulcus ; surface 

 covered by coarse unequal granulation of conical spinose tubercles ; three conspicuous 

 tubercles in sulcus at base of glabella. Length of head, 5 lines. 



This species belongs to that very restricted section of Lichas 

 named Acanthopyge by Hawle and Corda, in which the head seems 

 greatly simplified from the al^seuce of the middle and posterior 

 segmental furrows, leaving only 'one segmental lobe on each side 

 of the glabella. In this, and all other respects, our Australian 

 species most nearly resembles the Lichas Haueri (Bar.) of the 

 Ujjper Silurian limestone of the basin of Bohemia. It is rather 

 smaller, and, on comparison, has the head rather longer in proportion 

 to the width ; the segmental lobes are narrower, and the anterior 

 segmental furrows are not so straight and parallel, but seem to 

 narrow the middle portion of the glabella more by a regular curve, 

 the convexity of which is inward. 



Not uncommon in the Olive Schists of junction of Woori- 

 Yallock and Yarra (Stewart's station). 



Explanation of Figures. 



Plate XXII. — Fig. 11, specimen of head without the cheeks, natural size. The larger figure 

 OTer this is a magnified view of another specimen showing the glabella perfect, and the cheeks 

 within the eye-line showing the place of the eyes. 



Plate XXIII., Fig. 11. 

 HOMALONOTUS HARRISONI (McCoy). 



[Genus HOMALONOTUS (Konio). (Sub.-kingd. Artioulata. Class Crustacea. Order 

 Entomostraca. Tribe Phyllopoda. Fam. Trilobitidae.) 



Gen. Char. — Buckler scnii-elliptical, convex in the middle, obtusely pointed in front, lateral 

 angles not produced ; glabella indistinct, simple, subquadrate, with concave sides, narrower in 

 front than behuid, not reaching to the front margin ; eijes small, hiant, reniform, in the midst 

 of the cheeks, opposite about the middle of the glabella ; eye-line continuous from one side to 

 the other, all anterior to the eyes being nearly parallel with the margin of the buckler, pointed 

 in front, forming the usual small outward lobes over each eye, and from thence to the lateral 

 angles or a little in front of them ; thorax moderately arched, not distinctly trilobed, of 13 seg- 

 ments ; axis wider (if visible) than the lateral lobes, which have sub-truncate ends with large 

 distinct facets ; pleural sulcus, as in Calr/mene, arising from the posterior margin near the 

 undefined axis, and at half its length abruptly bent down again to it ; pi/gidium subtrigonal, 

 pointed, usually trilobed, with a distinct axis or none, the lateral ribs undivided.] 



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