SWAN PRIXCES ISLANDS. 57 



1. Beds of claystone, soft and decomposed at their junction with quartz 



rocks. 



2. Thick beds of grey subcrystalline limestone. 



3. Bhiish-grey claystone, containing true Devonian fossils, such as Pkacops 



or Dalmania pxincfata (both coiled and straight specimens), Orthoce- 

 rata, small Goniatites, and a large Bellerophon ? 



4. Dark limestone and purple shale. 



5. Yellow soft clays, containing Brachiopoda, Encrinite stems, &c. much 



decomposed and not describable. 



6. Grey shale contorted. 



7. Green and brown claystone, hard, with small nodules of brown lime- 



stone, yielding an excellent stone for building-purposes and quarrying 

 into large blocks. 



Turning now along the western side of the island, these strata 

 flank the quartz rocks for a few hundred yards, until they are cut 

 off by them at an indent of the land, but are succeeded again a 

 short distance further on by other fossiliferous strata, which are 

 evidently a continuation of the series just described, and are seen 

 in the cliffs in the following descending order. The distances given 

 are not the thicknesses of the beds, but the measurement of the 

 coast-line. 



1. Soft rotten yellow shales for about 100 yards, forming the junction with 



the quartz rocks. 



2. Thick and thin beds of grey limestone in grey and reddish shales for 



several hundred yards, fossiliferous, and dipping S. 65° W. at 60°. 



3. Beds of grey limestone in purple shales, containing large and small 



Orthocerata, Trilobites of the genus Thacops (both straight and coiled, 

 and very similar to P. bufo of the Hamilton beds, America), Cup- 

 corals, and a small Leptcena, for several yards along the coast. 



4. Yellow and brown shales, hard and soft beds, for about 40 yards, con- 



taining: — Orthocerata, small Goniatites, Cup-corals, one species very 

 similar to Cyathophyllum Decheni of the Eifel, C. ccesfitoaum, &c. ; of 

 Ti'ilobites, two or three species of Phacops, straight and coiled, P. 

 {Dalmania) punctata, very characteristic, and P. bufo, &c. ; of Brachio- 

 poda, LeptcBna, Orthis, Bhynchonella, Atrypa, and one Spirifer, all very 

 minute species ; small Encrinite stems, and minute fragments of bone 

 or spicula on yellowish shale, and a Calceola 1 



5. Green claystone, and purple and green shales with beds of grey fossili- 



ferous limestone, for about 50 yards ; full dip S. 30° W. at from 60° 

 to 70°. 



6. Yellow claystone with nodules of grey fossiliferous limestone for about 



13 yards, containing a Coral like Favosites Gothlandica. 



7. Purple and white shales with bands of limestone for about 33 yards, 



fossiliferous in the purple shales, and containing : — Cup-corals, Brachio- 

 poda {Leptcena, Spirifera, and Orbicula) ; and small Goniatites with 

 markings very similar to G. Marcellensis of the Hamilton beds, Ame- 

 rica ; of Trilobites, Phacops bufo &c. ; and a small " bone " of a fish. 

 The dip is S. 45° W. at 30°. 



8. Grey, purple, and satiny yellow shales, with beds of grey limestone for a 



distance of about 200 yards, very much disturbed and contorted, and 

 lying nearly perpendicular. Line of strike S. 75° E. 



9. A bed of trachytic stone, light-brown colour. 



10. Brown claystone, with small nodules of light-brown limestone, hard and 



thick-bedded (very similar to that observed at the S.W. promontory), 

 along with thin beds of grey limestone, for about 50 yards. Full dip 

 N. 75° E. ; well shown in cliffs, and lying nearly perpendicular. 



11. Soft claystone mixed in part with thin grey grit-stone, for 30 yards. 



12. Grey shale with limestone nodules for 13 yards ; full dip N. 20° E. 



