l62 



PROCEEDINGS OE THE GEOLOGICAL SOCIETY. 



one naturalist*, through whose careful investigations no less than 6 

 new genera and 24 new species have been added to the Annelidan 

 group of the Wenlock. We know of but one Wenlock species in 

 Scotland or Ireland. All except one species occurs in the true 

 Wenlock Limestone and shales : 4 species pass to the Lower Ludlow 

 (Helminihites, sp., Serpulites clispar, IS. longissimus, and Spirorbis 

 Leivisii) and 8 to the Upper (viz. Cornulites serpularius, Serpulites 

 dispar, S. longissimus, Tentacidites anglicus, T, ornatus, Trachyderma 

 squamosa, and 2 species of Arahelliies). 



Crustacea. — Ten new genera appear here for the first time ; it is 

 important to name them — Turrilepas, JEclimina, Oyphaspis, Deiplion, 

 Eurypterus, Hemiaspis, Pterygotus, Thlipsura, Oyihere, and Cytlie- 

 rellina. The entire Crustacean fauna consists of 27 genera and 78 

 species ; the Upper Llandovery transmits to it 7 genera and 14 

 species : 74 of the 78 species occur in the Wenlock Limestone ; and the 

 4 wanting species are Homalonotus cylindricus, Oeratiocaris ludensis, 

 Primitia ecccavata, and P. lenticidaris. The Woolhope beds hold a 

 remarkable Crustacean fauna, comprising 13 genera and 24 species : 

 this class and the Brachiopoda are the only two marked zoological 

 groups in this division of the Lower Wenlock series ; 12 of the Trilo- 

 bita are Upper Llandovery, and only 1 is distinctly a Woolhope 

 species, viz. Homalonotus cylindricus, Salt. The remaining 3 species 

 of Crustacea in the Woolhope are Primitia eoccavata, P. lenticidaris, 

 and Cythere Grindrodiana, Salt., all belonging to the Ostracoda ; 

 they are of no value. We thus rather unexpectedly find that the 

 Woolhope formation possesses groups of fossils almost equal to 

 those of the Wenlock Limestone ; such as the Actinozoa with 26 

 species, 18 of which are also Upper Llandovery; the Crustacea 

 with 24 species, 19 of which are Trilobites; the Brachiopoda 

 with 17 genera and 56 species out of the 21 genera and 96 species 

 known in the Wenlock Limestone. The poverty of the Crustacea 

 in the Tarannon and Denbighshire Grits might be expected from the 

 lithological characters of the rocks ; only 8 of the 78 species occur 

 in the former, and 5 in the latter horizon. Worth Wales has only 

 yielded 5 genera and 11 species, and South Wales 9 genera and 14 

 species ; only 3 species occur in Scotland — Turrilepas Wrightianus, 

 Beyrichia Klcedeni, and Pliacops JStoJcesii. The Irish species number 

 8 — CalymeneBlumenbachii, var. Allportiana, Oheirurus bimucronatus, 

 Encrinurus punctatus, E. variolaris, Pliacops caudatus, P. nitclus, P. 

 Stolcesii, and Proetus latifrons. The order Merostomata makes its 

 first appearance in the Wenlock through Eurypterus punctatus, 

 Hemiaspis Jiorridus, and Pterygotus problematicus, all in the Wenlock- 

 Limestone series. This group of Crustacea has been extensively 

 and critically worked out and illustrated in a masterly manner 

 by Dr. H. Woodward, F.R.S., in the volumes of the Palaeonto- 

 graphical Society, the Quarterly Journal of the Geological Society, 

 and the 4 Geological Magazine.' The suborder Eurypterida is repre- 



* G-. J. Hinde, Quart. Joum. Geol. Soc. vol. xxxvi. pp. 368-378. 



