154 TABULATE CORALS. 



escence of periodic expansions of the margins of the calices, 

 while mural pores are alleged to be absent. 



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

 Michigan) placed Chonostegites Clappi, E. and H., \n. Michelinia, 

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

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

 synonymous with M. (Emmonsia) cylindrica, 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 Chonostegites Clappi, E. and H. Mr Billings 

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

 absent in Haimeophyllum, these openings being present in all 

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

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

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

 latter to Michelinia, De Kon., later on. 



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

 be merely a variety of Haimeophyllum ordinatum, 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 Chonostegites 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 

 thatJ^f. intermittens, Bill., is in part identical vi\\h.M. cylindrica, 

 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 Chonostegites 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. 



