J. W. Gregory — Australian Fossil Echinoidea. 435 



and included L. angulosum, Herklots/ as a synonym ; but as Herklots 

 neither figured nor described the actinal side, a certain amount of 

 doubt must remain as to the accuracy of this determination. As 

 the present variety differs from the previously known species in the 

 same points as L. decagonalis, it need not be compared more closely 

 with them. 



Family, Cassidulid^. 



Genus, Cassidulus, Lamarck, 1801. 

 Systeme des Animaux sans Vertebres. 1801. p. 348. 



Species, Cassidulus florescens, n. sp. PI. XIL Figs. 2-4. 

 Floresco, to begin to blossom, referring to the imperfectly developed floscelle. 



Diagnosis. — Outline seen from above elongated, tapering to the 

 anterior end ; the greatest width is at the distal end of the postero- 

 lateral petals. The margins are long and fairly straight. The ends 

 are well rounded. Seen from the side it appears evenly rounded, 

 except for the flattened posterior slope. The ambitus is tumid. 



The actinal surface is concave; the peristome occurs at the summit 

 of the depression. The median bare band is imperfectly developed. 

 Apical system : before the vertex. A large central madreporite 

 and four genital pores. 



Ambulacra : Petals sublanceolate, flush ; open below. Th» anterior 

 is the longest. The antero-lateral pair is considerably shorter than 

 the postero-lateral pair. 



Peristome : anterior. Floscelle not well developed ; the bourrelets 

 are massive, but not prominent. Mouth pentagonal. 



Anus oval : broad and large. The subanal groove shallow, short 

 and broad. 



Dimensions. 

 Length 



Width: at apical system 



maximum... 



Height 



Distance of apical system from anterior end 

 ,, vertex „ „ 



,, mouth „ ,, 



Distribution. — Fyans Ford Hill, Moorabool Eiver; \\ miles 

 N.W. of Geelong. Middle Murravian. (Upper Eocene.) 



Type.— Brit. Mus. E. Presented by T. W. Eeader, Esq., F.G.S. 



Affinities and Differences. — This species is most clearly allied 

 to the Lutetian (Upper Eocene) Cassiduhs /aba, Defr.^ The most 

 important difference between them is in the structure of the petals : 

 these are longer and almost entirely closed in the French species, 

 whereas in the Australian form they are almost open ; the anus is 

 also longer and narrower and the test higher. Its shape I'esembles 

 that of Echinobrissus vincentiiius, Tate, but there is no reason to doubt 

 the accuracy of Prof. Tate's generic determination.^ 



^ J. A. Herklots, op. eit. p. 8, pi. ii. fig. 4. 



2 Defrance Diet. Sci. Nat. t. vii. 1817, p. 227. For figures and svnonymy see 

 Cotteau, Pal. FranQ, Echinides Eocenes, t. i. 1887, pp. 5] 0-512, pi. 139. 



3 Tate, op. cit. p. 280. 



