Lr. H. Hicks — Life Zones in Palceozoic Rochs. 441 



The species here described do not appear to be in any way related 

 to the forms which have been recorded ^ from New Guinea 



It may be observed in conclusion that an excellent Geological 

 Sketch-map of Western Australia by the Government Geologist, 

 Mr. Harry Page Woodward, F.G.S., has recently been issued, 



EXPLANATION OF PLATES XII. and XIII. 



[All the figures are drawn one -half the natural size unless otherwise stated.] 



PLATE XII. 



Fig. 1. Nautilus per ornatus, sp. nov. : a, lateral view, showing portions of the test, 

 and the course of the suture-lines ; b, peripheral view ; c, portion of the 

 test on the periphery, a and b are drawn one-fourth nat. size, c is drawn 

 nat. size. 



Fig. 2. Ammonites {Dorsetensia) Clarkei, sp. nov.: a, lateral view; b, front view ; 

 c, suture -line. 



Fig. 3. Suture-line traced from the specimen figured by Moore (Quart. Journ. Geol. 

 Soc. vol. xxvi. (1870), pi. xv. fig. 2) under the name of Ammonites 

 radians ; nat. size. 



Fig. 4. Ammonites {Stephanoceras) Australis, sp. nov.: «, lateral view; J, peri- 

 pheral view. 



Fig. 5. Ammonites [Stephanoceras), s-^.: a, lateral view; b, peripheral view. 



Fig. 6. Ammonites {Splicer ocer as?) TFoodwardi, s^^. nov.: a, lateral view ; b, peri- 

 pheral view. 



PLATE XIII. 



Fig. 1. Ammonites {Sphceroceras) semiornatus, sp. nov. : a, lateral view; b, peri- 

 pheral view. 



Fig. 2. Ammonites {Perisphinctes) Championensis, sp. nov. : a, lateral view ; 

 b, front view ; c, portion of the suture-line. The right-hand portion of 

 the first lateral lobe may not be quite correct, the fossil being badly- 

 preserved at this part. 



Fig. 3. Ammonites {Perisphinctes) robiginosus, s^. nov.: a, lateral view of fragment 

 devoid of septa ; b, section of whorl at S. 

 AU the specimens are from near Champion Bay, "Western Australia. 



II. — On some Life Zones in the Lower Palaeozoic Eocks of 

 THE British Areas, as defined mainly by Eesearches during 

 THE Past 30 Years. 



By Henky Hicks, M.D., F.R.S., F.G.S. 



{Continued from the September Number, page 405.) 



Middle Cambrian. 



FROM the foregoing remarks it will be seen that the Middle 

 Cambrian, as at present defined, is characterized by having 

 numerous Life Zones in which, usually, species .of the genus Para- 

 doxides, or of some closely allied forms, may be considered the 

 dominant organisms. Up to the present the genus Olenelliis, so 

 typical of the Lower Cambrian rocks, has not been found in direct 

 association with Paradoxides, but some of the associated genera 

 are equally characteristic both of the Lower and of the Middle 

 Cambrian.^ The Olenellus fauna, as a whole, seems to have dis- 



1 E. Etheridge, Jil., Records Geol. Surv. New South Wales, vol. i. pt. 3, 1889 

 (1890), pp. 172-179, pi. xxix. 



^ Mr. G. F. Matthew, who has worked out the zones in the Cambrian rocks of 

 New Brunswick, Canada, with much care and success, has recently described a new 



