ITALIAN GONIOPORA. 113 



92, Goniopora Vicenza (i3>10. 



[Crosara, near Marostico (Oligocene), coll. Michelotti ; Geol. Mus. Univ. Rome.] 

 Rhodarwa dissita, Angelis, Atti R. Accad. Lincei, i. (1895) p. 181 (text fig. 10). 



Description. — Corallum grew into small irregularly knarled nodules. The lobes or 

 branches are angular and flattened. The bases may be as small as 8 mm. in diameter. 



The calicles are of all sizes from 1-2 • 5 mm. and of varying depths, mostly shallow. The 

 shape of the calicle is variable owing to the irregularities of the surface, but regularly polygonal 

 on smooth parts. The septa (24) are thin and very pronounced, and with denticulate edges.* 

 Quite irregular in their fusions, most of them running singly towards the large open columellar 

 tangle which sent up pali-like points into the fossa. The interseptal loculi are large, open, and 

 pear-shaped, being mostly rounded peripherally. The walls too, when reticular, have large, 

 angular, open meshes. 



The single specimen was kindly lent for examination by the Director of the University 

 Geological Museum, Rome. 



The ends of the threads of the irregular columellar tangle evidently suggested the generic 

 name Rhodarcea, given it by Dr. Angelis (see Introduction, p. 16, on the genus Rhodarcea). 

 It is quite imlike any of the other Crosara forms, but on the other hand the surface aspect of the 

 calicles in the specimen is very like that shown in the fig. of Reuss' " P. pellegrinii " (S. Giov. 

 Ilarione) from the same district, in which also the denticulations were apparently altered by 

 aqueous action into smooth round knobs. The growth-forms are also somewhat similar, in 

 that they are both irregular, flattened, forking masses. 



The chief feature of interest is the fact that though there are the typical number of septa, 

 it is only in the smaller calicles with fewer septa that we find any traces of the typical formula ; 

 the secondaries with their adjacent tertiaries forming three-pronged forks against the wall. 



93. Goniopora Vicenza (i3>ll. 



[Crosara, near Marostico (Oligocene), coll. Michelotti ; Geol. Mus. Univ. Rome.] 



" Litharcm eximia" (Meneghini in litt.), Angelis, Atti R. Accad. Lincei i. (1895) p. 179, fig. 7 in 

 text. 



Description. — Corallum forms small circular discs upon a concentrically wrinkled epitheca. 

 The whole often greatly crumpled and attaining a thickness of 7 mm. 



Calicles 2 mm. in diameter, polygonal, depressed, with thick raised walls sometimes ridged 

 and sometimes round-topped. Seen by the naked eye, the slopes are closely striated by the 

 septa. The septa appear very crowded and 24 in number, descending into the calicles as rows 



* The denticles have here for the most part suffered post mortem alteration into thick 

 rounded knobs, as may be gathered by comparing them with the skeletal elements in the section which 

 are thin. 



q 



