BY JOHN MITCHELL. 1203 



mentioned a sertularian, Fenestella, Glaucanome, and others. These 

 are chiefly confined to the lower strata, associated with trilobites 

 of the lower zone ; and some of them bear a close affinity to 

 Devonian types. Crinoids are plentiful. 



The mollusca supply representatives of Orthis (socialis and 

 biloba being among the species), Atrypa (marginalis and reticularis), 

 Terebratula, Pentamerus (oblongus and galeatusj, Retzia, Pterinea 

 (pumila), Spirifer (asper and crispus), Rotella, Patella, Trochus 

 (bilix), Bellerophon, Euomplialus, Pleurotomaria, Ctenodonta, 

 Leptaena, Meristella, Lingula, Rhynchonella, Discina, Orthoceras, 

 and Megalodon (one species). Among the Spirifers is one seemingly 

 identical with a species obtained from the carboniferous rocks at 

 Jamberoo. 



Most worthy of special attention is the occurrence of Orthis 

 bihba, 0. socialis, Pentamerus oblongus, P. galeatus, Spirifer 

 asper, S. crispus, Atrypa reticularis, A. marginalis, Pterinea 

 pumila, Platyceras angulatum (I), and Orthoceras ccereesiense Hicks, 

 all typical of the Silurian age. A few of the many corals are 

 Favosites gothlandica, F. aspera, Heliolites iaterstincta, Receptacu- 

 lites Clarkei, Petraia bina, Ptychophyllum, Zaphrentis. 



The Bowning series has peculiar interest by reason of the 

 number of genera and species of trilobites it has yielded. My 

 researches have brought to light 14 genera representing 30 species. 

 They include Encrinurus punctatus, Cromus Reaumonti, Bronteus 

 Partschi, Calymene (4 sp.), Sphaerexochus mirus, Harpes, Phacops 

 (3), Cheirurus, Lichas, Asaphus, Proefois, and Acidaspis. Mr. Ratte 

 (ante pp. 1066-1069) has identified several of these. Of other 

 crustacean forms I obtained specimens of what appear to be 

 f ragmeDts of a species of Pterygotus and of Stylonurus. 



Of vertebrate remains no certain indications have been met with. 



Geological Age. — Reviewing the general character of the fossils, 

 especially those of the trilobite order, among which the genus 

 Acidaspis stands out prominently, I have little hesitation in 



