Dr. H. Woodward — Trilohites Jrom Shcmtung, N. China. 251 



II. — On a Collection of Trilobites from the Upper Cambrian 

 OF Shantung, North China. 



By Henry Woodward, LL.D., F.R.S., F.G.S. 



(Concluded from the May Number, p. 215.) 

 (PLATE XIII.) 



CONTINUING the notice of Herr H. Monke's paper on the 

 Trilobite-bearing limestone slabs of Yen-tsy-yai, the author 

 observes : — The very dense and solid, slightly ai'enaoeous lime- 

 stones of Yen-tsy-yai consist of horizontal slabs (from 1-2^ cm. 

 thick) of a dark bluish-grey colour, [p. 109] Whilst showing no 

 traces of fossils in their interior, the limestone slabs are on one side 

 (as shown on pi. ix) ^ often completely covered with the remains of 

 Trilobite carapaces, besides which are found only isolated very minute 

 shells of Brachiopoda. Between them are here and there irregular^ 

 lengthened furrows, which may be the tracks of the Trilobites ; on 

 the corresponding opposite parts of the slabs are similarly shaped 

 vermiform protuberances. It follows that the fossiliferous side is 

 to be considered as the natural upper part of the slabs. In a certain 

 number of the slabs either both sides or one only are covered 

 besides by a thin argillaceous stratum, which equally contains, 

 though less frequently, delicate remains of fossils ; in all the other 

 slabs the fossils present themselves en relief and often rest on a small 

 base of limestone, and therefore convey the impression of having 

 been originally covered by a thin argillaceous stratum, which later 

 on was washed away by water. 



Where the fossils are covered by the protective argillaceous layer 

 and could be developed by preparation, they are in an excellent 

 state of preservation ; where, however, the argillaceous layer is 

 wanting, the fossils are generally much worn and their delicate 

 sculpturing has disappeared. Complete carapaces of Trilobites hav& 

 not been found ; with the exception of a single instance in which 

 seven pleurae are still united in their original connection, all the 

 carapaces were broken up into single segments ; these present 

 themselves mixed together, exhibiting either their superior or in- 

 ferior side on the upper surface, and are much broken. Thi& 

 condition of things makes it, of course, difficult to find out the parts 

 which belong together ; on the other hand, it enables one to study 

 the structure of the carapace in all its details. A close examination 

 revealed the remarkable fact that the remains do not belong solely 

 [p. 110] to adult specimens, but that every possible degree of age, 

 down to individuals of microscopic size, are present in about equal 

 numbers. The explanation of this phenomenon may be that the thin 



1 Our Plate XIII is not copied from Herr H. Monke's beautiful plate, but is taken 

 from a part of the tine slab presented to the Britisb Museum by the Rev. Samuel 

 Couling, M.A., Ching-chow-fu, Kiao-chow, China, and was evidently obtained from 

 the veri/ same quarry which furnislied the slabs forwarded to Berlin by Herr 

 Bergmeister F. Koerfer, from the Upper Sinic Limestones of Yen-tsy-yai, where 

 a considerable trade in these slabs, crowded with remains of Trilobites, appears to be 

 carried on by the Chinese, under the title of ' petrified swallows ' ! 



