328 
TURBINOLIAD^. 
Milne Edwards, indeed, considers the Sphenotrochi with 
papillate and crisped ribs to be in no case later than the 
eocene deposits ; while those with smooth ribs he looks 
upon as invariably belonging to higher strata, and reaching 
to the present period : but this is a canon which a new 
species may at any moment overturn, if it be not already 
subverted by the 8. nanus (Lea) of the eocene of Alabama. 
Dr. E. P. Wright mentions, as a suspicious circumstance, 
that many pleistocene shells do exist in the bed of shelly 
sand, where these specimens were found. But this does not 
confirm Professor Milne Edwards’s rule ; for, so far as 
that could decide the question, it would prove not only 
that this crisped Coral is not recent, but that it is certainly 
as old as the miocene. 
Dr. Wright says : — “ I have reason to think, however, 
that they are not fossil;” and the same is my own impres- 
sion, though I can scarcely assign any definite grounds for 
it, except the fresh appearance of one or two of the speci- 
mens. Some of them are rubbed, and one is polished 
externally. 
The uniformity in size of the individuals, and the full 
development of the plates, indicate a probability that, 
minute as they are, they have attained adult age. 
[mixtus (/h*-^.).] 
[crispus (yhss.).] 
Wrightii. 
[Ceratotrochus (/oss,).] 
