134 



Cincinnati Society of Natural History. 



frondescent species in which the difference in size between the largest 

 and smallest cells is at all comparable with the difference stated to 

 exist by Edwards and Haime, I can assure him that, though rare, 

 specimens do occur in which very nearly those extremes of size do 

 exist. Lastly, it is almost certain that Edwards and Haime actually 

 had D'Orbigny's specimens before them, since, at the close of the 

 description, the} 7 accredit the specimens to the collections of D'Or- 

 bigny and D'Verneuil. 



More might be said upon this rather unpleasant subject, but it is 

 scarcely necessar}*, and I have little doubt that, alter a re-examination, 

 Dr. Nicholson will agree with me in considering his identification of 

 Jf. mammulata and M. frondosa as incorrect. In the course of this 

 memoir I frequently have occasion to criticise the views of Dr. Nich- 

 olson, as expressed by him in his "Genus Monticulipora." This work 

 shows extraordinary industry and observation, and I consider it en- 

 titled to the first rank in this branch of palaeontological literature. 

 While I intend to do every justice to Dr. Nicholson and the great 

 advance in our knowledge of this most difficult group of organisms 

 effected lyy his work, I am sorry to find it impossible to accept the 

 greater part of his general conclusions. 



Affinities and Zoological Position of the Monticuliporid^e and 



Fistuliporid^e. 



As regards the zoological affinities of the Monticuliporidce, and Fis 

 fuliporidce, some tendency has been developed on the part of palaeon- 

 tologists to remove them from the Ccelenterata, and to place them 

 among the Cyclostomatous Bryozoa. Little direct evidence in favor 

 of this step has been brought forward. Rominger (Proc. Acad. Nat. 

 Sci. Phil. 1866), boldly asserts that their affinities are with the Bry- 

 ozoa, though it must be confessed the arguments employed by him 

 are entirely insufficient to demonstrate the assertion. In 1873 Lind- 

 strom published (Ann. Nat. Hist. Ser. 4, Vol. xviii., p. 5, et seq.) his 

 theoiy of the development of the Monticuliporw. Nicholson ("Genus 

 Monticulipora"), after quoting at length Lindstrom's views of the 

 development, proceeds to criticise them, and argues with much effect 

 that they are untenable. In his discussion of the subject (loc. cit. p. 60), 

 he says: "The colonies of Ceramopora are usually (always ?) fixed, 

 bein^ attached parasitically by a portion of the whole of the lower 

 surface to some foreign body; whereas the corallum in the discoid 

 species of Monticulipora, supposed to be developed out of the 



