General History of the Marine Polyzoa. 181 



Ibid. (p. 110 Sep.). 

 Mucronella bicuspis, sp. n. 



This species is ranked by Waters as a variety of his 

 Smittia hiincisa *. I have not had the opportunity of 

 examining specimens of the fossil form, which was procured 

 from Tertiary deposits in South Australia and New Zealand ; 

 but, judging from the figure, I can hardly think that there is 

 sufficient ground for identifying it with M. hicuspis. The 

 general character of the orifice seems to me to be very different 

 in the two ; the lateral avicularia, a very constant feature of 

 the recent species, are wanting in the fossil, while the tubular 

 avicularia which are so conspicuous a characteristic in the 

 fossil are wanting in M. hicuspis. The oral denticle of the 

 latter is peculiar; but Mr. Waters has noticed some variability 

 in this portion of the structure. 



The difference between the characters of the cell-wall in the 

 two forms is remarkable. Not only are there more of the 

 large pores in S. hiincisa, but they differ in shape and 

 arrangement from those of the recent species. They form a 

 reticulate covering over the whole surface of the cell, whilst 

 in M. hicuspis they are disposed in a single line running 

 across the front of the cell. At the same time it must be 

 admitted that the superficial character of the cell-wall is liable 

 to much variation. Mr. Waters's experience as a student of 

 fossil Polyzoa entitles his judgment to much respect in a case 

 of this kind, and on the whole I prefer to leave the question 

 an open one. 



' Annals/ May 1884 (p. 358) f- 



Memhrampora marginella, sp. n. 



Two of the four cells figured bear ooecia ; the cells men- 

 tioned in the description as furnished with a large dark- 

 coloured operculum, " occupying nearly half the area," are 

 probably avicularian. 



Ibid. (p. 358). 

 Smittipora ahi/ssicola, Smitt. 



The genus Smittipora is, in my judgment, a synonym of 

 OnycJiocella, JuUien, the differences between the two being 

 quite immaterial. 



* Quart. Journ. Geol. Soc, August 1882, p. 272 ; ibid. February 1887, 

 p. 58. 



t From this point to the close of the " Appendix " the paging is that 

 of the ' Annals ' and not of the separate copies. 



