S52 Mr. Williamson on the Limestones 



Professor Phillips, who will perhaps be able to lay before the 

 public some more decided opinion as to their nature. 

 3. Entomostraca. 



Microscopic fossils are always with difficulty assigned to 

 their proper situations in the scale of organized life. This 

 difficulty was experienced by Dr. Hibbert amongst the Ento- 

 mostraca of Burdiehouse, and as a necessary consequence, we 

 experience the same amongst those of Ardwick. Throughout 

 the whole extent of the black bass, but especially amongst the 

 broken Uniojiida; near the seam of coal, we find abundance of 

 minute remains, generally about g^yth of an inch in length, which 

 can only be assigned to the above-named group of Crustacea. 

 I am uncertain whether there are one or two species: if two, the 

 one will be a Ci/pris, approaching very closely to Ci/p. Faba 

 in its beanlike form, but rather more elongated : the chief ob- 

 jection is, our not being able to detect the hinge. The other 

 species, if different, is in reality subunivalve, with a lateral 

 opening on one side: this is closely allied to the recent Daph- 

 nia, and is probably of Hibbert's genus Daphnoidea. It is of 

 the same size and outward form as the one above described, of 

 which it may only be the opposite side, showing the natural 

 groove : when largely magnified, I cannot compare it to any- 

 thing better than the berry of the coffee-tree after it is burned. 

 To judge from the drawings Dr. Hibbert has given, I think 

 our Daphnoidea presents the lateral opening much more di- 

 stinctly than any he has observed, from which ours differ in 

 being perfectly smooth instead of granulated. 



From these remains we have, without any other evidence 

 whatever being wanted, a strong proof of the freshwater 

 origin of this portion of the series. 



4. Remains of Fish. 



We now come to the group of remains which first attracted 

 my attention in the limestones of Ardwick. In June 1835 I 

 first detected remains of fish in the black bass, and have since 

 then at various periods made new additions to my collection. 

 As we have in no one instance discovered a perfect specimen, 

 the difficulty of identifying them with any known species must 

 of necessity be great, especially as they are in such a crushed 

 state that not even two scales can be found preserving their 

 relative positions. 



In the fifth number of the Zoological Journal, pubhshed 

 April 1825, is a drawing and description, by the late amiable 

 and talented E. S. George, Esq., and J. D. C. Sowerby, Esq., 

 of a remarkable bony plate, which the writers imagined to be a 

 portion of the palatal bone of some fish, found near Leeds in 

 the seam of coal commonly known in Yorkshire by the name 



