560 



bits rnore fully than fig. 3 the construction of the coral, 27 

 or 28 corallites probably existed around the periphery ; white 

 in the smaller (your) fossil as many, at least, may be coun- 

 ted along the margin. This Variation is greater than among 

 Zoantharia gener ally , yet 1 should be loath to make it the 

 basis of a specific distinctiofi. 



A point of greater consequence to geology is your fossil 

 coming from the Loiver Silurian series. In the Archives only 

 one species is described, and I do not Jcnow of another\ and 

 as M. Milne Edwards with M. Haime states, that it is confi- 

 ned to the Devonian System (Archives p. 210^, the following 

 localities are extracted so far as possible from original autho- 

 rities, that you may decide, whether their limitation is correct. 

 With the exception of Walch Pleurodictyum problematicum 

 is by each authorities directly referred to. 



Devonian localities. 

 Phillips, J. — Meadsfoot Sands. Pal. Foss. p. 19, 20. 

 Austen — Ogwell. Geol. Trans. Vol. VI. p. 468, 469. 

 D'Archiac and de Verneuil — Nehon. ibid. p. 407. 

 Milne Edw. and Haime — JVehou, Meadsfoot Sands (from 



Phillips), also Eifel, Aleje in Spain, Jefferson County 



V. S. — but no allusion is made to the localities 



given by Goldfuss. 

 Silurian localities. 

 Goldfuss — Abentheuer, Braubach. Petref p. 113. 

 D'Archiac and de Verneuil — Daun, Niederrossbach in 



addition to Abentheuer and Braubach. Geol. Trans. 



Vol. VI. p. 407. 

 Walch o/'Knorr — Hausberg near But%bach between Giessen 



and Friedberg. Naturg. der Verstein. 3. Theil p. 50. 



and 230. 

 Goldfuss cites Walch's (Knobr's) delineation Tab. II*. 

 and X.b., and Milne Edwards with J. Haime T.X.; but nei- 

 ther refers to the localities above given. Probably they were 

 not deerned admissible. L. 



NB. The localities cited by Goldfuss, d'Archiac et 

 de Verneuil and Walch or Knorr are all now known to 

 be Devonian, i. e. Lower Devonian or Terrain Rhenan (Spi- 

 rifer-Sandstein). Rod. J. Murchison. 



