AUSTRALIAN CAINOZOIC (tEHTIARY) DEPOSITS. 53 



number towards the ambitus. The larger tubercles have a swollen 

 scrobicule, a crenulated boss, and a small perforated mamclon, and 

 the upper extremity of the boss has its crenulation projecting up- 

 wards and outwards like a frill (PI. IV. figs. 3 & 4). The spaces 

 between the tubercles are more or less crowded with larger miliaries ; 

 and theso are again surrounded here and there by smaller. In the 

 lateral interambulacra there are also several rows of the same kind 

 of tubercles as in the anterior; the rows contain more tubercles, 

 but do not approach the ambitus or the apical system more than 

 do those of the anterior spaces. In the intcrambulacral spaces, be- 

 tween the large tubercles and the apical system are crowds of large 

 and small miliaries. 



The ambitus is sharply curved from above downwards, and is 

 rendered irregular in its outline by the slight projection of portions 

 of it from which the tubcrculation of the actinal surface radiates in- 

 wards. On this surface (PI. IV. fig. 2) the posterior ambulacra are 

 bare and broad, and coalesce, forming a broad bare actinal shield, a 

 few miliaries only existing. As a whole the actinal surface is flat, 

 the mouth being very slightly sunken, and that only anteriorly; but 

 between the ambulacra just noticed is a projecting plastron covered 

 with secondary tubercles at the sides, and with miliaries on the 

 top of its keel. The actinosome is large, elliptical, broader than long, 

 and the sides are rounded and project slightly backwards. The 

 posterior lip projects slightly, and has large miliary tubercles on it. 

 The anterior phyllodcs arc well developed, and extend nearly to the 

 edge of the test ; and the posterior are recognizable by one or two 

 large slit-shaped pores. The tubercles of the actinal surface radiate 

 in lines from points in the lateral and anterior interambulacra at the 

 ambitus, and the tubercles increase in size as they approach the 

 actinosome with its comparatively bare surrounding plates. A very 

 ill-developed, extremely narrow fasciole (visible under a magnifying 

 power of 10 diam.) is seen on part of the test below the tubercular 

 area. The frill-like crenulation is present on the actinal surface. 



Length 2| inches, breadth 2\ inches ; height at posterior part 

 J^inch, at apical system / ; inch. 



Locality. — Mouth of the Sherbrook river, with Ewpatagu* Laubd. 



The resemblance of this form to Maretia planulata, Gray, is per- 

 fect, with the exception of the partial and extremely small fasciole. 



Eupatagtjs PvOTrxDrs, sp. nov. Plate III. figs. 14-17. 



The test is thin, and the outline of the ambitus is nearly circular, 

 there being a slight flatness posteriorly where the anus is situate on 

 a truncation which slants slightly from above downwards and in- 

 wards. The vertex is nearly central, and thence there is a slight 

 slope to the apical system ; the slope continues anteriorly, and then 

 dips down suddenly to the ambitus. Behind the vertex a keel 

 passes backwards horizontally beyond the line of the posterior am- 

 bulacral petals, and the slope increases to the margin of the pcri- 

 proct. The rest of the posterior part is obliquely truncate, the 

 surface of the truncation being slightly concave from side to side. 



