ba 
Contributions to Micro-Paleontology. 117 
most interesting in point of size, no sufficient character has 
yet been given which would separate them into different 
species. ~ Indeed the very characters most insisted upon are 
those which seem most certainly to point to their identity with 
D. nitida, Verrill. 
Distichopora coccinea, Gray. 
In his monograph of the genus, the Rev. J. E. Tenison- 
Woods has given a figure of this species, and states that he 
does not think the species has yet been figured. It may be 
pointed out that when the species was described by Dr. Gray 
it was also figured (Proc. Zool. Soc. 1860). 
XIV.—Contributions to Micro-Paleontology.—Notes on some 
Species of Monticuliporoid Corals from the Upper Silurian 
Rocks of Britain. By H. ALteyNe Nicuorson, M.D., 
D.Se., Regius Professor of Natural History in the Uni- 
versity of Aberdeen. 
[Plate VII.] 
Ir has long been my intention to give a. detailed account of 
the microscopic structure of the Monticuliporoid Corals of 
the Wenlock Limestone of Britain, so far as known to me. 
I have found, however, that the accomplishment of this would 
demand more time than is at present at my disposal; and I 
therefore, in the meanwhile, publish the following notes on 
the minute structure of some of the commoner Wenlock 
Morticuliporoids*, in the hope that they may prove useful to 
other workers in the same field. From the brief descriptions 
and accompanying figures of structure, it will, I think, be 
found easy to recognize the types which I have had under 
observation, and this is the special object which I have had in 
view. On the other hand, I have found great difficulties as 
to the nomenclature of the forms here described, and I have 
not been able to clear up these difficulties to any extent. The 
earlier observers of these fossils, as, for example, Mr. Lons- 
dale, necessarily founded their names upon macroscopic cha- 
* Besides certain ramose Monticuliporoids which I have as yet imper- 
fectly examined, the Wenlock Limestone contains various incrusting 
forms (such, for example, as the curious type figured by Milne-Edwards 
and Haime under the name of Monticulipora papillata), which require for 
their elucidation a more detailed investigation than I have hitherto been 
able to undertake. 
