ON CRETACEOUS POLYZOA. 311 



50. Petalopora pulchella, forma Clavicavea regularis ? 1852, d'Orb., 



' Terr. Cret.,' p. 941, pi. 773, figs. 

 12, 13. 



51. „ „ „ Cavca regularis, 1852, d'Orb., I. c, 



p. 943, pi. 774, figs. 1, 2. 



52. „ „ „ „ costata, d'Orb., Z. c.,p. 944, pi. 



774, fig. 4 (non pi. 601, figs. 

 19-22). 



53. „ „ „ „ appendicnlata, d'Orb., I. c, p. 



944, pi. 774, fig. 5. 



54. „ „ „ „ flexuosa, d'Orb., Z. c, p. 947, 



pi. 774, figs. 9-12. 



The other forms indicated by d'Orbigny I have not distingaished in 

 the Chatham material. 



1834. Genus Heteropora, Blainville.' 



This genus, as characterised by Dr. Pergens, includes species belong- 

 ing to the following genera of d'Orbigny : — Glaviclausa, Glausa, Cavea, 

 Clavicavea, Sparsicavea, Muliia-escit;, Zonopora, Multizonopora, and typical 

 Heteropora. The characters of the species found in the Chatham Chalk 

 are so diverse that I feel compelled to make a slight departure from the 

 classification of Dr. Pergens in the special arrangement of this peculiar 

 group of Polyzoa : — 



Heteropoka, Pergens = Glausa, d'Orbigny, ' Terr. Cret.,' p. 893. 



55. Heteropora obliqua, d'Orb., 'Terr. Cret.,' p. 895, r,\. 623, fio-s. 



18-21. 



56. „ irregularis, d'Orb., Z. c, p. 897, pi. 624, figs. 9-12; 



pi. 766, figs. 10-12. 



57. „ Francqaua, d'Orb., /. c, p. 898, pi. 766, figs. 13-15 



(mentioned as being bad in the Paris collection ; but 

 the examples are very fine in my Chatham collec- 

 tion). 



HE'rrcROPORA, Pergens = »Sparsica?;ea, d'Orb., 'Terr. Cret.,' p. 948. 



58. Heteropora Carantina, d'Orb. (Perg., ' Rev. des Bryoz.,' p. 372), 



' Terr. Crut.,' p. 950, pi. 775, figs. 1-3. 



59. ,, Francqana, d'Orb., I. c, p. 951, pi. 775, figs. 4, 6 



(figures bad). 



60. „ Ligeriensis [=i MuUizonopora, d'Orb.), I. c, p. 927, 



pi. 772, figs. 4-6. 



61. „ variabilis ? (MuUicrescis), d'Orb , Z. c, p. 1077, pi, 800, 



figs. 3-7. 



1887. Genus Cavarinella, Marsson. 

 02. Cavarinella ramosa {?)^Cavaria ramosa, Hagenow. 



This species appears to be rare in the Chatham Chalk. I have only 

 one very poor example, which I place here for the jsresent. 



' See Dr. Pergens, lievis. des Bryoz., p. 3G9. 



