210 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



scribed from the Carboniferous Limestone proper, illustrating 28 

 genera out of 33 (or nearly every occurring genus is represented), 

 and the above number of species out of the known 225. The 

 4 genera wanting in the Limestone are Anihrapalcemon, Belinurus, 

 Pygocephalus, and Canclona. The Ostracoda number no less than 

 15 genera and 107 species ; the Phyllopoda 8 genera and 36 

 species ; the Trilobita 3 genera and 8 species. 



Yoredale Beds. — The Ostracoda through the genus Bairdia 

 (6 species) and KirTcbya (2) ; the Phyllopoda through Beyrichia (5), 

 Estheria (1) ; and Griffithides mucronatus (Trilobita), complete the 

 Crustacean fauna of this horizon. 



Millstone Grit.' — No Crustacean remains known. 



Lower Coal-measures. — 13 species of Ostracoda, 8 of Phyllopoda, 

 and 4 Pcecilopoda, with 3 species of the genus Anihrapalcemon, a 

 Macrurous Decapod, 2 species of which first appeared in the 

 Calciferous Sandstone (A. Maconochii, Ether., and A. Wood- 

 wardii, Ether.). A. dubius, Prestw., A. Gfrossarti, Salt., and A. Bus- 

 sellianus, Salt., belong to the Lower and Upper Coal-measures. This 

 is the earliest known appearance of the order Decapoda. This ancient 

 type has been found both in the Coal-measures of Europe and 

 North America. Anihrapalcemon is related to the living Galathea. 

 Of the suborder Xiphosura or Pcecilopoda we possess 2 genera, 

 Bellinurus and Prestivichia, this last allied to Neolimulus of the 

 Upper Silurian. The Penny-stones of Coalbrook Dale yield Prest- 

 wichia rotundata (Limulus). All the thoracic and abdominal seg- 

 ments in Prestivichia are ankylosed. The earliest appearance in 

 time or commencement of existence of the Xiphosura is in the 

 Ludlow rocks ; no Xiphosuran has yet been detected in the Devo- 

 nian. Pygocephalus Gooperi, Huxl., and P. Jluxleyi, Woodw., occur 

 in the Lower Coal-measures. These Podophthalmatous Stomapods, 

 with the Decapod Anthrapalcemon (3 species), carry back in time 

 the higher order of the Crustacea. 



Middle Coal-meastjres. — Anthrapalcemon dubius, Bellinurus bet- 

 lulus, Konig, Beyrichia arcuata and B. Binneyana, Estheria, Bei- 

 nertiana and E. striata, are all the Crustacea known in the Middle 

 Coal-measures. 



Upper Coal-measures. — 10 genera and 16 species compose the 

 Crustacean fauna of the Upper Coal-measures — Ostracoda 6, Phyllo- 

 poda 7, Poecilopoda 1, and Anihrapalcemon Grossarti. 



