486 ON THE rOLrZOA of the red chalk of HUNSTANTON. 



branches dichotomouslj. The zocecia are oval, but attached : area 

 oval ; walls thick. This is a poor and unique example of the 

 species ; I cannot follow d'Orbigny in the other characters drawn 

 up by him. 



Hahitat, On Belemnites. Fossil * No. 44. 



Horizon. Red Chalk, Hunstanton. 



Genus Hippothoa, d'Orb. 

 43. Hippothoa simplex (d'Orb.). 



1851. HippotJwa simplex^ d'Orb. Terr. Cret. v. p. 385, pi. 711. 

 figs. 5-8. 



The forms that I have been able to identify are certainly not 

 members of the Hippotlioa group as now understood; but, as a 

 set of four cells appear to beloug to H. simplex, d'Orb., or a close 

 ally, I place them here provisionally. They are all that I have met 

 with adherent to Red-Chalk fossils, and are too characteristic to be 

 overlooked. 



Habitat. On Inoceramus. Fossil No. 40. 



Horizon. Eed Chalk, Hunstanton. 



EXPLANATION OF PLATE XIX. 



Polyzoa from the Eed Chalk of Hunstanton, Norfolk. 

 (The objects enlarged are magnified about 15 or 20 diameters.) 



'Fig. \. Prohoscina angustata, d^Ovb. Variety: 1 «, natural size ; li, enlarged. 

 Var. : 1 c, nat. size ; 1 d, enlarged. 



2. P. irregularis, sp. nov. : 2 a, nat. size ; 2 h, enlarged. Var. : 2 c, nat. 



size ; 2 d, enlarged. 



3. P. uberrima, sp. nov. : 3 a, nat. size ; 3 b, enlarged. 



4. P. gracilis, Keuss, var. Be^issii, nov. : 4 a, nat. size ; 4&, enlarged. 



5. P. himstantoncnsis, sp. nov. : oa, nat. size ; bb, enlarged. 



(i ■ , var. amjjliata, nov. : 6 a, nat. size ; 6 b, portion enlarged ; 



6 c, nat. size ; (i d, portion enlarged. 



7. P. Jessoni, sp. nov. : 7 a, nat. size ; 7 b, enlarged. 



8. P. gigantopora. Vine, var. : 8 a, nat. size ; 8 b, portion enlarged. 



9. P. bohemica, Novak, var. : 9 a, nat. size ; 9 b, enlarged ; 9 c, nat. size ; 



9d, portion enlarged. 



10. Diastopora h/cnstanfonensis, sp. nov.: 10a, nat. size; 10b. portion en- 



larged. 



11. ■ , var. : 11 a, nat. size ; 11 b, portion enlarged. 



12. J). Jessoni, sp. nov. : 12 a, nat. size ; V2b, portion enlarged. 



13. Memhranipora gaultiva, Vine. var. : 13 a, nat. size ; 13 b, enlarged ; c, d, 



portions enlarged. 



Discussion. 



Dr. HiNDE commented on the imperfect preservation of the 

 specimens exhibited, and the difficulty of satisfactorily determining 

 species from such specimens. 



* The fossil No. Ao {Tcrt-bratula hiplicata) has attached to it several examples 

 of Vi'ehhina (?), which seem to simulate the characters of M. obliquu ; but a 

 careful examination of the two forms will be sufficient to disprove any suj^posed 

 relationship between the polvzoon and the protozoon. 



