THE 



GEOLOGICAL MAGAZINE 



NEW SERIES. DECADE III. VOL. IX. 



No. X.— OCTOBER, 1892. 



L — FuRTHEE Additions to Australian Fossil Eohinoidea. 



By J. W. Gregory, B.Sc, F.G.S. ; 



of the British Museum (Natural History). 



(PLATE XII.) 



DURING the last two years four papers have appeared upon the 

 Australian Cainozoic Echinoids, contributed by M. Cotteau/ 

 Prof. E. Tate,^ Herr A. Bittner,^ and myself.* These add consider- 

 ably to our knowledge of the fauna ; they show that it is Eocene 

 and Oligocene, instead of Miocene, and that it is remarkably varied 

 and rich in genera. I am now able to add one or two more species 

 to the list, and at the same time take the opportunity of ref^ring to 

 one or two changes proposed by Prof. Tate and Herr Bittner. 



Fam. Laganid^. 

 Genus, Laganum, Gray, 1825. 



J. E. Gray. "An attempt to divide the Echinida " Ann. PhU. 1825 



vol. X. p. 428. ' 



Species, Laganum decagonale, Lesson, Var. rictum,^ n. var. PI. XII 



Fig. 1. 



Synonymy (of the species). See A. Agassiz. Eevision of Echinoids. Illus. Cat 



Mus. Comp. Zool. No. 7, 1872, p. 148. 

 Scutella decagonalis, Lesson, 1827, in Poiret. Scutello Diet. Sci. Nat. t. xlviii. p. 229. 

 Lagana decagona, Lesson, 1834, in Blainville Actinologie, p. 215, pL xviii. fig. 3. 

 Laganum decagonuni, Lesson. L. Agassiz. Mon. Echinod. ii. Scutelles, 1841, p. 112, 



pi. xxiii. figs. 16-20. 



Diagnosis (of the variety). 



Form : elongated elliptic ; the posterior end is longer and 

 narrower than the anterior ; the anterior end is semicircular ; the 

 sides taper backward. The base is flat ; the margins are tumid, and 

 are separated from the slightly conical apex by either a flat platform 

 or a slight broad depression. 



1 G. Cotteau. Echinides nouvelles ou peu connues. No. IX. Mem. Soc. Zool. 

 France, t. iii. 1890, pp. 546-550, pi. xii. figs. 13-18. No. X. Ibid. t. iv. 1891, 

 pp. 629-630, pi. xix. figs. 10-14. 



2 B,. Tate. A Bibliography and revised list of the described Echinoids of the 

 Australian Eocene, vrith descriptions of some new species. Trans. Eoy. Soc. South 

 Australia, vol. xiv. pt. 2, 1891, pp. 270-282. 



^ A. Bittner. Ueber Echiniden des Tertiars von Australien. Sitz. k. Ak. "Wiss. 

 "Wien, Bd. CI. Abt. i. 1892, pp. 331-371. 



^ J. W. Gregory. Some Additions to the Australian Tertiary Echinoidea. 

 Geol. Mag. Dec. III. Vol. VII. 1890, pp. 481-492, Pis. XIII.-XIV. 



° From ringor, rictus, to open the mouth widely. 



DECADE III. — yOL. IX. — NO. X. 28 



