358 G. E. YIliJE ON THE FAMILY DIASTOPOEID^. 



Devonian. Ceramoioora huronensis, Nicholson, Geol. Mag. 1875. 

 Silurian, TJppEE. incrustans, Hall, Pal. of New York, vol. ii. 



■ okioensis, JVicholson, Ann. of Nat. Hist. 1875. 



Berenicea irregularis, Lonsd., Sil. Syst. p. 679, pi, 15. Hg. 20. 

 SiLUKiAN, Lower. heterogyra, M'Coj, Pal. Eoss. pi. i.e. fig. 17. 



It is impossible to look over this list without some sense of shame 

 that this indiscriminate nomenclature should be allowed to influence 

 the minds of those who undertake the task of introducing to the 

 palaeontologist new species of fossil Diastoporidge. Between the 

 Berenicea of Lamouroux, the Ceramopora of Hall, and the Diasto- 

 pora of Smitt and Busk there is a wide difference — so much so that, 

 though all the genera are incrusting, there are special features about 

 the Palaeozoic that are not found in the Secondar}^, Tertiary, or re- 

 cent forms. Eor the present many of the species in this list may be 

 conveniently left with the Diastoporidse ; but I would strongly ad- 

 vise those who are in possession of good characteristic specimens of 

 Secondary forms to allow them to be examined by some competent 

 authority, so that this review may be completed, because some few 

 that are catalogued are not Diastopora or even Diastoporidos. 



The generic characters of Lamouroux's Berenicea, as given by 

 M'Coy, are as follows : — " Parasitic : cells united in a spot-like 

 crust, radiating from a centre; adhering throughout, not circum- 

 scribed ; mouth at the distal extremity of each cell; substance suh- 

 memhranaceous "*. In the 'Brit. Pal. Fos.' p. 44, M'Coy very |)ro- 

 l^erly checked Lamouroux's wider characters ; and his description of 

 the genus suits more particularly some at least of the Palaeozoic 

 forms. The B. heterogyra, M'Coy, of the .Lower Silurian rocks of 

 Coniston, is a remarkable species. Prom his description it seems to 

 me to be a true Diastoporid of a very peculiar type ; but the size of 

 the cells in the length (three to the spn ce of one line), occupying the 

 same space as the ten or eleven pores crosswise, is very unusual. 

 M'Coy says nothing about the interspaces between the cells in 

 his species. The B. irregularis of Lonsdale is very insufficiently 

 described ; but as the locality of his fossil is given (Dudley), iden- 

 tification is not so difficult. The species, however, requires rework- 

 ing : and in doing this I find that the cells are very sparsely punc- 

 tate ; and when sections are made for microscopic examination, the 

 interspaces between the cells of this species are plain, and the mode 

 of bifurcation and the attachment of the cells are also of a peculiar 

 type. The cell-pores, too, are not so fully developed as in the genus 

 Ceramopora, nor are the cell-mouths so distinctly marked. It seems 

 to me, however, to be a very unwise procedure to substitute another 

 name for these Silurian species ; I therefore propose that M'Coy's 

 definition for the genus in ' Brit. Palaeozoic Fossils ' be adopted, and 

 entirely restricted to the " very thin calcareous foliaceous " forms of 

 the Silurian rocks of this country at least. 



In the genus Ceramopora, Hall, we have an altogether different 

 type of the family Diastoporidge. In this genus we have an in-/ 

 crusting polyzoon with pores separated by interspaces as well as t!lie 

 * Carb. Foss. of Ireland, 1844. 



