536 W. M. Hutchings — On some Lake-District RocJcs. 



of the same rules whioli have been employed in satisfactorily deter- 

 mining the order and the characteristic organic remains of the more 

 recent systems. Surely it is not too much to hope that the day is fast 

 approaching when these Eozoic formations will be reduced to their 

 natural order as fossil -bearing systems, comparable in all respects 

 (except in the greater paucity of their organic remains) with the 

 Post-Archsean systems which at present form the accepted members 

 of our great geological scale. 



EXPLANATION OF PLATE XIV. 



Fig. 1. Olenellus Callavei. Glabella in relief, showing the characteristic shape, 



the lobes and furrows, and the broken base of the 



occipital spine. 



Fig. 2. Do. Side elevations. 



Fig. 3. Occipital lobe with base of central process. Posterior 



aspect. 

 Fig. 4. — Fragment of hinder part of glabella, etc., from above, 



showing size and length of a broken occipital spine. 



Fig. 5. Do. Side elevation. 



Fig. 6. Fragment of part of head, showing marginal and 



interior ridges. 

 Fig. 7. Terminal part of free cheek with marginal ridge, and 



genal and " interocular " spines. 



Fig. 8. Do. Another and smaller example. 



Fig. 9. Eye lobe. 



Fig. 10. Do. Smaller example. 



Fig. 1 1 . One of the anterior segments of the axis, showing the 



form and position of the median spine. 



Fig. 12. Do. From central parts of axis. 



Fig. 13, 14. Do. Profile views. 



Fig. 15. Segment of axis near posterior end. 



Fig. 16. Sub -terminal (?) segment of axis, showing central and 



lateral tubercles. 



Fig. 17. Pygidium. 



Fig. 18. One of the proximal pleurae, showing general form, 



pleural groove, and falcate extremity. 



Fig. 19, 20. Pleurae from near posterior end of thorax. 



Fig. 21. Superficial ornamentation of test. (Magnified.) 



Fig. 22. Ditto. (Magnified.) 



Fig. 23. Doublure for attachment of hypostoma. 



Fig. 24. Toung form of 0. Callavei, showing general form and characters of the 



glabella, eyes, frontal margin, etc. 

 Fig. 25. Do. Another example. 



(All the fragments figured, except Figs. 21 and 22, are of the natural size.) 

 Figs. 18, 19, 20, 24, are from my own Collection, the remainder are in the 

 Collection of the "Woodwardian Museum, Cambridge. 



PLATE XV. 



Fig. 26. Olenellus Callavei, Lapw. Theoretical restoration, natural size. 



11.^ — Petkological Notes on some Lake District Eocks. 

 By W. Maynard Hutchings, Esq. 



DURING- the last three years I have at various times collected 

 and studied rocks from the Lake District. Some of them are, 

 I think, of sufficient interest to render them worth describing. It is 

 my opinion that a great deal of very interesting petrological work 

 still remains to be done among these rocks, and that when they are 



