BRYOZOA. 359 



figure equally as well under his FENESTELLIDJE as under the POLY- 

 PORID.E. Lyropora Hall, would go partly in one family, and the 

 remainder in the other. And why separate Pinnatopora and 

 Septopora from AcantbocJadia and Ichthyorachis? Simply 

 because the former have only two rows of zooecia, and the lat- 

 ter three or more? Such a difference is surely not sufficient to 

 outweigh the important points of agreement above mentioned; 

 no, it does not require a very extended knowledge of the Fene- 

 stellids to become convinced of the inadequacy of variations in 

 the number of ranges of cells as foundations for families, yes, 

 scarcely even for genera. As to the three genera which he 

 groups under the name DIPLOPORID.E, I should say that Actino- 

 stoma is founded upon a species of Fenestella, in which the 

 radial ribs of the opercular closures of the zocecial orifice were 

 not obliterated by deposits of calcareous material. I have 

 seen these more or less distinctly preserved in a number of the 

 FEXESTELLID.E (species of Fenestella, Polypora, Lyropora and 

 Pinnatopora) and believe that they were generally present in 

 these Bryozoa. Acanthopora Y. & Y., stands in the same re- 

 lation to Pinnatopora* As regards Diplopora Y. & Y., I shall 

 view the division in the light of a valid genus, but not upon 

 the characters mentioned by Mr. Vine and the authors of the 

 genus. For discussion of this point see remarks upon the genus 

 further on. With regard to the POLYPORIU.E and THAMNISCIDJE, 

 nothing farther need be said, as my opinion of them is already 

 sufficiently expressed. 



Waagen and PichPs arrangement of the FENESTELLID.E differs 

 somewhat from that proposed by Tine. They divide the family 

 into three sub-families, of which the first, the FEXESTELLIN.E, con- 

 tains, FenesteUa, Fenestralia Prout, Septopora, Lyropora, 

 Ptilopora McCoy, Helicopora Claypole, and Archimedes 

 Lesueur. In the POLYPORIN.E they propose to include Poly- 

 pora. Phyllopora, Synocladia and Dendricopora DeKoninck, 



* The name Acanthopora has priority over Pinnatopora of Vine, having been pro- 

 posed in 1875, but as it is less appropriate than the latter and was erected upon what I 

 believe to be defective specimens, and only as a provisional subgenus under Glauco- 

 nome, it seems desirable to drop the name in favor of Vine's, which was well charac- 

 terized and established for the reception of species not intended to be covered by 

 Acanthopora, 



