4 Tertiary Fossils in South Australia, 



possess features peculiarly their own. I proceed, at once to 

 describe the specimens to which the accompanying drawings 

 refer. 



No. 1. Salicomaria Sinuosa (Hassal). This fossil is the 

 prevailing one of the beds. It is found everywhere, and is so 

 common that I have never yet found a square inch of stone 

 belonging to the deposit which did not at least contain a 

 dozen of its fragments. Busk identifies with this species the 

 S. farciminoides. The variations in the form of the cells 

 which I have witnessed, after examining hundreds of spe- 

 cimens, make me believe this to be very proper. 



S. gracilis and S. tenuirostris, have both been found 

 fossil, but are not drawn, as they are both figured in Busk's 

 catalogue. 



No. 2. Cauda angalata, the connection of the branches by 

 transverse tubular fibres is not, according to Busk, a character 

 of either generic or specific importance. It was only known 

 to occur in one species till the discovery of that here 

 described. 



No. 3. Gellepora Garnbierensis (Busk). This is the character- 

 istic fossil of the formation. It grew to immense size. In 

 appearance it very much resembled a true branching coral ; 

 was hollow in the stem, and was very much and irregularly 

 branched. 



No doubt it existed in the form of a reef, and probably 

 gave rise to the coralline formation. I have seen it, where 

 sections of the bed have been exposed, branching up like a 

 strong tree ten or twelve feet high. Probably such an im- 

 mense operation as a coral reef by Bryozoa is a solitary 

 instance, but we have long since learned that in nature the 

 magnitude of the work bears no proportion to the workman. 

 No drawing can give a, character by which it can be known, 

 for it varies so much in form. It may, however, be described 

 as irregular branches studded with cells, which are perforated 

 with one minute opening. The branch is hollow inside, and 

 the interior of the cavity is smooth and finely ribbed. The 

 thickness of the tube varying with age ; cells apparently 

 growing from without, and irregularly disposed. 



No. 4. Gellepora Hemisphcerina (Busk). This is a lenti- 

 cular polyzoary, more or less flattened, but generally in shape 

 like a double convex lens. It varies in size from that of a 

 sixpence to that of a lentil. The cells are very small and 

 equal in dimensions. 



No. 5. Gellepora Nwrn.mularia, (Busk). Polyzoary obliniar 



