POLYZOA. 143 



Locality. Upware. 



Affinities and differences. Nodicrescis tubcrculata (D'Orb. Terr. 

 Cret. V., pi. 800), and N. verrucosa, (Homer, Kreide, pi. V., f. 

 26, p. 23), are allied to this remarkable Upware species, but 

 neither of them present the characteristic confluence and oblique- 

 ringed arrangement of N. annulata. Ceripora papularia is very 

 similar in gross appearance, though a more slender and anasto- 

 mosing structure, but according to d'Orbigny, it is quite a distinct 

 genus (Reptomulticlausd). 



HETEROPORA (REPTONODICRESCIS), sp. 



An encrusting species growing upon an oyster or Plicatula. 

 The cells are large and close set, and the intermediate pores are 

 sparsely scattered between them. It may be the young and rep- 

 tant condition of H. annulata, but the cell openings are rather 

 larger. 



Locality. Upware. 



HETEROPOKA (MULTICRESCJS) ARBUSCULA, n. sp. 



(Plate vn. fig. 17 a, 6.) 

 Ceriopora polymorpha, Cat. Mus. Pract. Geology, 1878, p. 7. 



Description. Polyzoarium rather bush-like, attached by a broad 

 base, from which one or many trunks may arise. Branches taper- 

 ing, circular in section. 



Over the surface are seen (i) large cell-openings, circular, 

 and with slightly prominent peristome ; these are either very few 

 and irregularly scattered, or grouped in patches, or arranged in 

 irregular zones. The areas between these are occupied by (ii) the 

 numerous small pores which are about half the diameter of the cell 

 mouths. 



In places the cells are arranged in distinct spirals, but generally 

 they seem to be quite irregular in their distribution. 



The colony usually measures about one inch in height and 

 breadth. 



Localities. Upware, Brickhill. 



Affinities and differences. This polyzoon has been very 

 generally called by collectors Ceriopora polymorpha of Goldfuss, 



