478 Eev. T. Hincks's Contrihutions toivarch a 



dale (Gippsland) in wliicli none of tlie cells are acuminate." 

 (Quart Journ. Geol. Soc, Aug. 1882.) 



'Annals,' August 1881 (p. 65 sep.). 



Mucronella jjorosa, sp. n. 



This species must, I think, be considered a form of jMac- 

 Gillivray's M. EUerri, as Mr. Waters has suggested *, though 

 there are striking differences between them. The most 

 remarkable feature of M. Ellerii is the line of spinous pro- 

 cesses with rounded heads situated on the peristome, which is 

 much elevated. These are entirely absent in il/. jmrosa, and 

 the peristome is not raised ; consequently the general aspect 

 of the zoarium in the two forms is strangely dissimilar. As 

 a result probably of the elevated spinous peristome in ]\f. 

 Ellerii the massive central mucro is not developed, and the 

 large avicularium occupies a place some way down within 

 the lower margin. The surface of the cell is more or less 

 covered with nodules distributed amongst the pores. 



M. idorosa is much simpler in character. There is a total 

 absence of the spinous processes ; the centre of the lower 

 margin bears a massive mucro, much swollen at tlie base, 

 on one side of which, turned slightly inward, is placed the 

 avicularium, with a broad rounded mandible. Large spatu- 

 late scattered avicularia are present at times on both forms. 

 In a specimen from Singapore or the Philippines numerous 

 smaller avicularia, elevated above the surface and resembling 

 the oral form, are distributed over the cells. 



The cells in M. Ellerii are suberect. The small rounded 

 avicularium on the margin at one side of the mucro is charac- 

 teristic of M. porosa. The latter may stand as il/. Ellerii^ 

 form porosa. 



M. vultw\^ Avhich Mr. Waters would also refer to M. 

 Ellerii, is, I think, entitled to specific rank. Its remarkably 

 large cells, decumbent, not suberect or oblique like those of 

 M. Ellerii, its exceptionally massive mucro, its large avicu- 

 larium, with its elongate, finely pointed mandible bent abruptly 

 inward at the top, its large, articulated, oral spines, form a 

 group of distinctive characters. The cells of M. vultnr differ 

 not only in size but in general character from those of M. 

 Ellerii and its form porosa. 



* " Australiau Bryozoa," ' Annals' for Reptember 1887, ]). ll»4. 

 t " Contributions " &:c., p. 98 (sep.). 



