no 



the encrinal limestone (No. 3) : it is succeeded by the coral- 

 line shales. The overlying shales are not very fossiliferous, 

 but at the top of the falls the heavy bedded limestone 

 carries the fossils characteristic of zone No. 6. 



In the river bed below Rock glen, many fine corals 

 of the genera Heliophyllum, Zaphrentis and Favosiles are 

 found in association with numerous bryozoans and an 

 occasional trilobite. 



At a bend in the river, about -4 miles ( -6 km.) below the 

 bridge at Marshall's mills, a section about 75 feet (22 • 8 m.) 

 thick is exposed. The top of the lower shales and the 

 bed containing Leiorhynchus laura are situated about 27 feet 

 (8-2 m.) above the water. The upper shales are somewhat 

 obscured here by the loose material, and the thick upper 

 limestones are poorly exposed. The characteristic fossils 

 of the coral shale are very plentiful in the debris scattered 

 along the river. The most satisfactory collecting ground 

 is just below the steel bridge near where Marshall's mills 

 used to stand. The section here includes about 27 feet 

 (8-2 m.) of the lower shales succeeded by about 22 feet 

 (6-7 m.) of limestone and shale, all capped by about 4 feet 

 (1-2 m.) of gravel. The best collecting is from the river 

 up to the second firm bed, five feet (1-5 m.) above the 

 Leiorhynchus shale (No. 2). Fossils of zones 1, 2, 3 and 4 

 are very plentiful in this locality. Besides the numerous 

 species of corals, bryozoans and brachiopods, Tornoceras 

 uniangulare (Conrad), Bactrites obliqueseptatus arkonense 

 Whiteaves, Pentremites, etc., are likely to be found. Some 

 of the rarer fossils to be obtained here are: — Microcydus 

 discus Meek and Worthen, Cladopora cf.fischeri (Billings), 

 Trachypora elegantula (Billings), Nucleocrinus elegans 

 (Conrad), Camarotoechia thedfordensis Whiteaves, Cyrtina 

 hamiltonensis (Hall) and, Phacops rana (Green). 



ANNOTATED GUIDE.— Continued. 



KUome"^ The country is very flat to the eastward of 



Thedford, with little of geological interest to be 

 observed until the Thames river is crossed at 

 St. Marys. Salt Yvells were formerly operated 

 near Park Hill. 

 38 • 49 m. St. Marys — Alt. 1 ,082 ft. (38 • 49 m.) . Although 

 61-9 km. no rock exposure is to be seen from the train, 



