!24 MADREPORARIA. 



Lake Unni as belonging to the same " species." In addition to the primary improbability 

 of two forms so far apart being so exactly similar, there are further reasons for doubting the 

 validity of this interpretation, reasons based upon the difficulty of interpreting the fossils. 

 See on this point pp. 96-98. 



Reuss records (I.e.) a "third species like P. deshayesiana Mich." (which is a true Porites) 

 from the same hard limestone, but the details could not be made out. 



111. Goniopora Vienna Basin (4)3- 



[Niederleis, Lower Austria (Miocene [Tortonian]) ; Vienna Museum.] 



Porites leptoclada, Reuss, Fos. Cor. Ost^Ung. Miocans in the Denkschr. K. Akad. Wiss. Wien, xxxi. 

 (1872) p. 261, pi. xvii. figs. 3 and 4. 



Description. — Corallum presumably dendroid, the branches forking at a somewhat blunt 

 angle ; only cylindrical fragments of stems and short portions of branches, frequently compressed, 

 were discovered. 



On the older portions the calicles are shallow, crowded, polygonal, 1 • 5-2 mm. in diameter, 

 and marked off from one another by rows of coarse flattened grains. Twelve short, thick septa 

 with edges composed of from 2-4 similar granules, and their sides covered with sharp points. 

 In smaller calicles the pali can hardly be distinguished from the septa, but elsewhere they form 

 a ring of 5-6 moderately large grains, with a very small central tubercle often deep down. 



On younger compressed branchlets the walls, though not high, rise into ridges with rather 

 sharp edges. 



This coral is said to be very common at Niederleis and " also at Nodendorf " ; and the 

 same is said to occur rarely at Porzteich and on the Muschelberg near to Nikolsburg (Moravia). 

 The one figured by Reuss is from the first-named locality in the Vienna Basin, and we must 

 confine our attention to it. 



It might be interesting to inquire whether, considering the close similarity of these 

 inrracalicular skeletons, this dendroid form might not be a branching tuft-formation of the same 

 coral whose encrusting stages are described under the last heading. The type of calicle was 

 that still found on branching Gonioporcc. That encrusting forms may easily pass into tufts we 

 have already seen : compare, for instance, G. Great Barrier Beef 1 and IS. 



112. Goniopora Vienna Basin (4)4. 



[Forchtenau near Odenburg [west of the Neusiedler See] (Miocene [Tortonian]) ; 



Vienna Museum.] 



Porites incruslans, Reuss, Fos. Cor. Ost.-Ung. Miocans in the Denkschr. K. Akad. Wiss. Wien, xxxi. 

 (1872) p. 261, pi. xvii. figs. 5 and 6. 



N.B. — It would have been doubtful how far the following description referred to an actual 



specimen or was modified by reference to the description of the "Porites incrustans Def." 



(which may have been based upon Michelin's P. colleyniana, see p. 117) of Milne-Edwards and 



Haime, had not the figures been clear and good, and had it not been expressly stated thai 



the specimen figured was from Forchtenau. 



