154 TABULATE CORALS. 



escence of periodic expansions of the margins of the callces, 

 while mural pores are alleged to be absent. 



At a still later date, in 1876, Dr Rominger (Foss. Cor. of 

 Michigan) placed Chonostcgitcs Clappi, E. and H., [nMickclinia, 

 and referred AlicJielinia intermittens. Bill., in part to the same 

 species ; while he considered M. intermittens as also in part 

 synonymous with M. [Emmonsia) eyiindrica, E. and H. 



Having carefully examined an excellently-preserved series of 

 specimens of Haimeophyllum inordinatum, Bill., I have failed 

 to discover any character by which it could be specifically 

 separated from Clionostegites Clappi, E. and H. Mr Billings 

 was undoubtedly in error in supposing that " mural pores " are 

 absent in Haimeopliylltim, these openings being present in all 

 parts of the corallum where the tubes come into actual contact. 

 I regard Haimeophyllnm, Bill., therefore, as a synonym of 

 Clionostegites, E. and H., and shall discuss the relations of the 

 latter to MicJielinia, De Kon., later on. 



In the second place, I think Michelinia intermittens, Bill., to 

 be merely a variety of HaimcopJiylluin ordinatiun, Bill., with 

 the tubes more extensively in contact than is usual in this 

 variable species. As the latter species is in my opinion the 

 same as Clionostegites Clappi, E. and H., it follows that M. in- 

 termittens. Bill, is a synonym of C Clappi, as it is in part made 

 to be by Dr Rominger. I need only add that there cannot be 

 the slightest hesitation in rejecting Dr Rominger's further view 

 that J/, intermittens. Bill., is in part identical with vJ/. eyiindrica, 

 E. and H., since Billings expressly states that his species was 

 founded upon a single specimen ; and it cannot, therefore, pos- 

 sibly be partly referable to one species and partly to another. 



Before discussing the relations between Clionostegites and 

 Michelinia, and the possible propriety of uniting them with one 

 another, it will be well to briefly describe the structure of C 

 Clappi, the type and the only satisfactorily differentiated .species 

 of the former genus. 



