NIAGARA GKOTJP. 



137 



Genus CLADOPORA {nov. gen.). 

 [Gr. xkaSoi, surculus, and ■s'opoj, 'pora.^ 



Ramose or reticulate ; branches cylindrical or slightly compressed, terminations terete ; eoral 

 composed of a series of tubes or cells radiating equally on all sides from the axis, and opening 

 upon the surface in rounded or subangular expanded mouths ; cells more or less closely ar- 

 ranged, but not always contiguous, and apparently destitute of septa or rays. 



The corals of this genus form a very distinct and well characterized group, sometimes in 

 masses of closely arranged, slender, parallel or branching stems, and in other species of beautiful 

 reticulated forms. Where the cells are empty and well preserved, the openings on the surface 

 are margined by a thin projecting lip or calicle on the lower side, having a nearly semicircular 

 outline, and gradually sloping below into the substance of the branch. In worn specimens the 

 surface has no prominences, and the apertures of the cells are subangular or rounded, being 

 a little more expanded than the cavity below. Where the cells are filled with calcareous matter, 

 they frequently separate in prismatic forms like Favosites, but there is no evidence of trans- 

 verse septa. The cells are not always contiguous, and there is often a space between the walls, 

 which appears to be solid in one or more species. 



These corals belong apparently to a group, some species of which have been referred to 

 Alveolites by different authors, but which do not possess the essential characters of that 

 genus ; neither do they belong to the Genus Ch^tetes or Favosites. All the species yet 

 known are branching, the reticulated forms being produced by coalescing of the branches, 

 which, at the extremities, are often free or ramose. Probably some of the smaller reticulated 

 species have been referred to Retepora, from which they are readily distinguished by the 

 branches being poriferous on all sides, as well also as in the form of the cell. 



The following species, and several of its congeners, have the habit and mode of growth of 

 the Sebiatopora, while others approach in this respect to Pocillopora. 



524. 1. CLADOPORA SERIATA {n. sp.). 



Pl. XXXVIII. Fig. la-m. 



Coral composed of a series of nearly vertical stems, more or less closely arranged in nearly 

 parallel series, forming glomerate masses ; stems sometimes bifurcating, internally composed 

 of a series of tubes radiating from an axis, and gradually enlarging" towards the mouth ; 

 openings somewhat transverse, closely arranged in alternating series, and margined on the 

 lower side by a projecting semicircular lip ; stems sometimes quite solid. 



This is a very beautiful and characteristic species, and one of the most abundant corals in 

 the Niagara group. It is often seen in the compact limestone, where the characters of the cells 

 are not so readily examined ; but it is known from any other coral by the numerous cylindrical 

 [ Paljeontology — Vol. ii.] 18 



