THE RED CHALK OE HUIJ^STAISTTON. 469 



Habitat. Type on Terehratula hiplicata; var. A, on a Belemnite. 

 Fossils ISo. 10 and 10*. 



Horizon. Red Chalk, Hunstanton. 



This species is only known to me by a few rather imperfect 

 examples beside the type form, and some of these may easily be 

 mistaken for other species. In the type (on Fossil Xo. 10, figs. 2 a, 

 2 6) the originating point of the colony is situated in the midst of a 

 clustered mass at the base of the zoarium. Prom out this mass 

 another colony (or branch ?) passes off to the right, and towards the 

 upper right-hand side is apparently the nucleus of ai^other. Alto- 

 gether, the general habit of the Polyzoon, the peculiar mode of deve- 

 lopment, and arrangement of cells in the colony, justify my charac- 

 terizing this form by a new name. A very simple form of the 

 species is found on one of the larger fossils. In this example the 

 largely-clustered zoarium, as found in the type form, has apparently 

 not been reached. 



11. PROBOscmA UBERRIMA, sp. nov. (Plate XIX. figs. 3 a, 3 h.) 



The zoarium of this beautiful species is similar in many respects 

 to that of P. irregularis, except that the zocecia, v^hich are feebly 

 punctate, could not be consistently described as " irregular " in the 

 same sense as with that species. The distinctive features of this, 

 however, are the well-developed ovicells (three in number) right 

 across the middle of the zoarium. Each gonoecium (ovicell) is 

 separated from its near neighbour by the proximal extremity of 

 an intervening cell. The aperture of each ovicell is small, and in 

 one, in the area below the aperture, there is a circular dotted (punc- 

 tured?) patch which occupies the greater portion of the facial 

 surface of the ovicell. This is the only example of the species that I 

 have met with in the Pted Chalk. 



Habitat. (3n Inoeeramus ? sulcatus. Fossil Xo. 11 a. 



Horizon. Ped Chalk, Hunstanton. 



12. Proboscina gracilis, Peuss, var. Eetjssii, nov. (Plate XIX. 

 figs. 4 a, 4b.) 



Zoarium adherent, simple or branching : branches originating 

 from a single cell, and gradually widening towards the distal extre- 

 mity. Zooecia smooth (?), arranged alternately in the older part of 

 the branch, clustered and contiguous in the upper ; peristome 

 circular, slightly raised. 



Habitat. On Terebratula biplicata. Fossils Xo. 12a, type; 

 branching form Xo. 12. 



[Since this paper was read, a separate copy of Dr. E. Pergens's 

 " Eevision des Bryozoaires du Cretace figures par d'Orbigny," 

 premiere partie : Cyclostomata f , has come to hand. Without enter- 



t [Bull. See. Beige aeol. Palcont. Hydro!, vol. iii. (for 1889), U9d, pp. 305- 

 400.]" 



a. J. G. S. Xo. 183. 2l 



