215 



The epithecai ig in bands, is variable in, amount, and covers 

 more or less constriicted portions of the corallum. It com- 

 mo'nly surrounds the calice, but may be entirely absent in very 

 short, subdiscoid forms. The costse are eq^ual, granular, and 

 prominent. They correspond to the septai, and except on the 

 inferior part of the corallum are occasionally concealed by thef 

 banded epitheca. 



The septa are short, dentate, strongly granulose, and vary 

 in number from 24 in young to 32 or 34 in adult examples. 

 They are in six systems with four cycles, but the higher orders- 

 are incompletely developed. The lateral bud has only the 

 three first orders of septa present, and its calice presents a more 

 symmetrical appearance than that of the parent, where septa 

 of higher orders are irregularly developed. Similarly the. 

 subdiscoid forms have only the principal orders of septa pre- 

 sent in their calices. 



The pali are large, irregular in shape, and placed as a rule 

 before the primary aaid secondary septa. The columella, 

 though usually papillary, is fascicular in one or two worn, 

 calices. There may be numerous small papilli, or a few larger 

 ones, in which case they resemble the pali. The columella 

 and pali are only partially developed in young calices. 



A small amount of endotheca is present in some examples. 



Tlie corolla vary from 1.5 mm. to' 8.5 mm. in height. Thos& 

 figured are respectively 8 mm., 6 mm., and 3 mm. high, Th© 

 calices are all about 3 mm. in diameter, except that of the- 

 bud, which is smaller. The base varies in diameter from 3 

 mm. to 4 mm. 



Locality, dsc. — Eocene. From the Cape Otway beds, 12 

 examples; Wilkinson's No. 4, one example. A single speci- 

 men also from the Adelaide bore. 



EXPLANATION OF PLATES. 



Plate I. 

 Fig. 



1. Trochocyathufi Maplestonei—a, corallum, 3 diam.; 6, calice, 6 diam. 



2. Trochocyathiis infracompressus — a, corallum, 3 diam.; h, calice of a 



smaller example, 6 diam. 



3. Trochocyathus planicostatus — a, corallum, 3 diam.; h, calice, 6 diam. 



4. Trochocyathus Adelaidensis — a, corallum, 3 diam.; h, transverse section' 



of the calice of another specimen, 6 diam. 



Plate 11. 



1. Placotrochiis Puehlensis— a, corallum, 2 diam.; b, calioe, 4 diam. 



2. Placotrochus ivfieclus — a, corallum, 2 diam. ; h, outline of the same, nat. 



size ; c, calice (much worn) of another specimen, 4 diam. 



3. Ceratotrochus clinatun — a, corallum, 3 diam.; b, calice, 7 diam. 



4. Pleuropodia Otwayensis — a, corallum of short specimen with lateral 



bud, 4 diam.; b, calice of the same, 10 diam.; c, corallum showing 

 probable strobilation, 4 diam. ; d, outline of tall bent corallum, nat^ 



