AN AUSTRALIAN AMPHIPORA. 



By R. Etheridge, Junr., Director and Curator, Australian 



Museum, Sydney. 



(Plates xliv.-xlv.) 



In his "Monograph of the British Stromatoporoids," Prof. 

 H. A. Nicholson said, " so far as known ADipliipora is repre- 

 sented by one species only, viz. : the form described by 

 Phillips under the name of Vaunopora ramosa (Fig. and 

 Descript. Pal. Foss., p. 19.) This remarkable species occurs 

 in yasfc numbers in the Devonian Rocks of Germany and 

 Devonshire, apparently occupying in the former region, as 

 probable in the latter also, a definite horizon in the upper 

 portion of the Middle Devonian series (the Ramosa-Bjinke of 

 Schulz)."! 



Tlie researches of Mi-. A. J. Shearsby, of Yass, have revealed 

 many interesting fossils from the rich Murrumbidgee beds, not 

 the least interesting being that about to be described. 



In A. ramosa, Phillips the coenosteum, or calcareous skeleton, 

 is in the form of slender cylindrical stems, which may or may 

 not increase by dichotomy. Each branch is occupied by a 

 longitudinal, axial, central canal, or tube, which may be inter- 

 sected by tabulfe, transverse or funnel-shaped. The general 

 skeletal tissue is of the Stromatoporoid type, continuously 

 reticulated, but compact instead of being minutely porous. 

 Irregular zooidal tubes xadiate outwards from the axial tube 

 to open on the surface by definite apertures. The appearance 

 of the coenostial surface varies, either these apertures are 

 visible with vermiculate or tuberculate margins, or the cylin- 

 drical branches are surrounded by a zone of lenticular vesicles, 

 enveloped bj^ a delicate apparently imperforate calcareous 

 membrane. The general tissue is completely reticulate and 

 there are neither radial pillars nor concentric laniinfe as dis- 

 tinct structures (Xic]tnJ!inii.) 



1 Nicholson— Mon. Brit. Stromatoporoids, Pt. i , 1886, p. 109. 



