Stf/ld.sterida' fi'om the Victorian Tertiarics. 177 



very close, but the characteristic feature on which the genus was 

 founded, namely the absence of dactylopores from the inner side 

 of the cyclosysteni, is so constant, except in the tips of the 

 growing branches, that the retention of the genus appears advis- 

 able. 



Localities. Eocene : Orphanage Hill, Fyansford ; Filter 

 Quarries, Batesford ; Cape Otway ; Clifton Bank, Muddy Creek. 

 Miocene : Grange Burn (Forsyth's), near Hamilton. 



Genus Sporadopoka, Moseley 



Sporadopora dichotoma. INIoseley.^ 



The fossil specimens do not seem separable from the recent 

 species described by Moseley. 



The specimens consist of fragments up to about an inch 

 and a half in length. The stouter pieces are cylindiical and 

 about as thick as one's little linger, while those from nearer the 

 distal end are elongate oval in transverse section and give out 

 flattened lobes, just as shown in Moseley's figure.'^ The surface 

 of the corallumis marked by short almost vermiculate lines which 

 are merely the outer extremities of the irregular branching, and 

 anastomosing calcareous bars, of which the whole corallum is 

 built up. The structure is denser neai^er to the surface than in the 

 axial portions as shown both in thin sections and in the broken 

 ends of the branches. Piercing the outer wall are a great number 

 of circular pores varying greatly in size, and scattered irregularly 

 over the surface. The gastropores, as also the dactylopores, are 

 of several sizes, and viewed externally are, as a rule, choked with 

 the clayey matrix in which they were found. Frequently the 

 gastropores are plugged with a grain of siliceous sand, which is 

 at times disastrous when a slice is being ground down. The 

 varying size of the gastropores is not mentioned by Moseley in 

 the text but is shown clearly in one of his figures.^ It is rather 

 difficult to arrive at any exact proportion of the number of gastro- 

 pores to that of dactylopores, as the latter, being smaller, are 

 more hidden by the matrix, which even several boilings in 



1 Phil. Ti-aiis., 187S, p. 4-2!). 



2 hoc. cit., pi. 34, fijf. 1. 



3 Loc. cit., pi. 35., fife'. 2. 



