J. W. Gregory — Australian Eehinoidea. 487 



Apical system large ; ornamented with tubercles ; radials narrow. 

 Anus slightly elliptical. 



Ambulacra : narrow above with small tubercles ; but wide at the 

 ambitus with large tubercles; both sets are uncrenulate and im- 

 perforate. The bosses are large and fill up nearly the whole of 

 the areola. Two rows of small flat granules run up the centre 

 of each area at the ambitus, but disappear above. Eleven plates 

 in a vertical series. 



hit" r ambulacra. — The bare median band at the summit of each 

 area is bounded on either side by a row of large, and a row of small 

 granules. At the ambitus the number of granules widen, and there 

 are three rows of subequal granules on either side. No primary 

 tubercles. Fifteen plates in the vertical series. 



Mouth large ; in a concavity. Buccal slits broad. 



Dimensions. 



Diameter 19 mm. 



Height 12 ,, 



Width of ambulacral area at ambitus 7 ,, 



Width of interambulacral 6 ,, 



Diameter of anus 3 ,, 



Distribution : Middle Murravian, Morgan, S. Australia (preserved 

 in the Ipswich Museum). 



Coelopleurus is a typically Cainozoic genus, but has not previously 

 been recorded from the Australian Tertiaries. The type-specimen 

 of the new species is broken, but the apical disc and most of the 

 abactinal surface, a complete ambulacrum and the halves of the two 

 adjoining interambulacra are shown : all the points in the anatomy 

 of the test can therefore be determined. Coelopleurus paucituberculatus 

 is very easily distinguished from any other species of the genus by 

 the complete absence of primary tubercules on the interradii (the 

 character which has suggested its name), and by the persistence to 

 the apical disc of a pair of granules on either side of the bare 

 median area. In the latter feature it resembles Coelopleurus siudensis, 

 Dune, and SI., which is apparently its nearest ally. It can be easily 

 distinguished from this by the absence in the new species of the 

 primary ambital interradial tubercles. 



Fam. Clype astride. 



Gen. Clypeaster, Lam., 1816. 



Clypeaster gippslandicus, M'Coy. 



Prod. Pal. Victoria, Dec. vi. 1879, pp. 33-5, pi. lix. 



There is one well-marked specimen in the collection which is of 

 interest, as the species is usually characteristic of the uppermost beds 

 of the South Australian and Victorian Cainozoic series. 



Subgen. Monostychia, Laube. 

 Monostychia australis, Laube, sp. 

 Sitz. k. Akad. Wiss. Wien. lix. Abth. i. 1869, p. 190, fig. 3. 

 The collection includes several specimens of this species, and one 

 belonging to the var. elongata. 



