468 MR. G. R. VINE ON THK POLYZOA OF 



1889. Prohoscina awfustata^ Vine, Proc. Torksh. Geol. 8gc. vol. xi. 

 p. 265. 



Small colonies belonging to this species are found on several of the 

 fossils in the lied Chalk, and generally associated -with, other forms. 

 In the Cambridge Greensand a rather ill-preserved example was 

 found (the only one — adherent to a small phosphate nodule), which 

 I placed originally as f^tO)Rato'pora (jracilis. I believe, after a re- 

 examination of the fossil, the proper location ought to be here. 

 D'Orbigny, in his description of the species, refers to it as being 

 composed of two lines of longitudinal alternating cells, and this, 

 generally, is the character of the Red-Chalk fragments. Eeuss 

 figures his species as partly uni- and partly bi-serial, and the 

 Cambridge -Greensand form more closely resembles that of the 

 " Planer " than d'Orbiguy's form from Le Mans. 



Habitat. On Terehratula. hij)licata. Fossil ^o. 1 m. Also on 

 Inoceramus and Ammonites. 



Horizon. Cambridge Greensand: and lied Chalk, Hunstanton. 



9. Peoboscina. P.UGOSA (?), d'Orb. 



1852. Prohoscina ntgosa, d'Orb. Terr. Cret. v. p. 853, pi. 633. 

 figs. 6, 7. 



Amongst the rarer Polyzoa of the lied Chalk there are a few 

 examples similar to the beautiful species figured by d'Orbigny 

 quoted above. In only one small specimen are the cells in the 

 branch arranged in three rows ; and in this only some of the cells 

 .are rugose, as in the form from Le Mans. There are, however, a 

 few examples of a branching Polyzoon encrusting Terehratuloi in 

 the Eed Chalk that may be regarded, if not identical with d'Or- 

 biguy's species, at least as belonging to a variety of the same. The 

 arrangement and character of the cells are similar, and the rugose 

 markings on one cell (many of the others are broken or abraded) 

 are very perfect. The diameter of the branches in the British form 

 is fully 1 millim. against the " 1 demi-millimetre " of the Le Mans 

 form. 



Habitat. On Terehratula biplicata. Fossils !No. 9 a and Xo. 11b. 

 Also on Pnoceramus and Ammonites. 



Horizon. Cambridge Greensand ; Red Chalk, Hunstanton. 



10. Peoboscina ieeegulaeis, sp. nov. (Plate XIX. tigs. 2rt, 2 Z> ; 



Variety A, figs. 2 c, 2 d.) 



Zoarium repent; very irregular in its mode of growth and 

 general habit. The zoarium is unbranched, but made up of many 

 divergent cells, which, springing from a central or semi-central 

 nucleus, diverge in a variety of ways from that point. The zocecia 

 are slightly ventricose in the originating cells and in the more 

 fully developed zoarium ; but the zooscia here also are very irregular. 

 Go7ioeciurii double-celled ; having the bust-like aspect of a pouter- 

 pigeon in the type species, but generally speaking the gonoccium 

 is a largely inflated cell. 



