482 J. W. Gregory — Australian Echinoidea. 



tion. Its characters agree with those of the specimen from Bairnsdale 

 described but not named by Dr. Duncan. This species differs from 

 L. australice mainly by the very deeply impressed areolae which 

 occur in the latter. 



Spines. 



The collection includes a considerable number of spines which 

 closely resemble those of Goniocidaris, Pliyll acanthus and possibly 

 also of Heterocentrotus. The only plates to which the spines of the 

 Glypliostomata might be referred are too inperfect for description 

 (B.M. E 3378-9). 



Fam. Cassiduliixe. 

 Gen. Cassidulus, Lam. 1801. 

 Cassidulus longianus, sp. nov. PL XIII. Figs. 1-3. 



Outline from above elliptical, somewhat pointed anteriorly. Abac- 

 tinally it is evenly rounded ; the vertex slightly precentral. Actinal 

 surface slightly concave with the mouth in the centre of the depres- 

 sion. A wide median bare band runs backward from the mouth. 



Apical system at vertex. Five radial and four basal pores. 

 Madreporite large, occupying whole of centre of the system. 



Ambulacra. — Petals sublanceolate ; flush; open below; pores 

 yoked. The single pores of the extrapetaloid plates are on the 

 adoral margin. Petals nearly equal : the posterior laterals are 

 slightly narrower and less lanceolate than the anteiolatei'al. 



Peristome anterior : at deepest part of the slight actinal depression. 

 Floscelle very prominent. Phyllodes very narrow at oral end, but 

 expanding into wide areas with five pores in the outer row of each 

 side. Bourrelets very prominent. Mouth pentagonal. 



Anus long, narrow and oval ; situated at upper end of a long 

 narrow groove, which however barely influences the posterior margin. 



Dimensions. Largest specimen. Type, Fig. 1. Type, Fig. 2. 



Length 



Width 



Height 



Distance of apex from anterior edge 



Distance of mouth ,, 



Maximum width of poriferous zone : 



antero-lateral ambulacrum 

 Maximum width of poriferous zone : 



postero-lateral ambulacrum 

 Length of antero-lateral ambulacrum .. 

 Length of postero- ,, ,, 



Cassididus has not previously been described from the Australian 

 Tertiaries. The genus is mainly Cretaceous, but a few species occur 

 in the Eocene. Cassidulus longianus is a well-marked species : the 

 bare median band, one of the features of the subgenus Pygorhynchus, 

 the long anus and short petals form a series of characters to be met 

 with in no other species of the genus. It most resembles some of 

 the United States Cretaceous forms such as C. subquadratus, Conrad. 1 



1 T. A. Conrad, Journ. Ac. Nat. Sci. Phil. [2] iv. p. 291, pi. xlvii. fig. 19. 



