OCT 4 1898 



A Further Cambrian Trilobite from 

 YoRKE Peninsula. 



By R. Etheridge, June., Hon. Fellow, Curator, Australian 

 Museum, Sydney. 



[Read November 2, 1897.] 



Plate lY., figs. 1-3. 



In 1884 Dr. Henry Woodward described* two Cambrian 

 Trilobites from the Parara limestone of Yorke Peninsula, to 

 which he gave the names of Dolichometopus Tatei, and Cono- 

 cephalites australis. Since then Prof. R. Tate has described! 

 two others from the same district — Olenellus (?) Pritchardi and 

 MicrodisGUS suhsagittatus. 



Quite recently the Mr. W. Howchin transmitted to me a 

 portion of the cephalic shield of another Trilobite, found by him 

 at Ardrossan, that is in my opinion congeneric with Woodward's 

 C. australis, but differing specifically, as I hope to show in the 

 sequel, by a very important character. It will, however, be 

 necessary in the first place to review our position in a generic 

 sense. Dr. Woodward, following my determination of the Caro- 

 line Creek Trilobites, in Tasmania, referred his species to the 

 genus Conocephalites, Barrande, both of us using this name as it 

 was then commonly accepted. Through later researches amongst 

 Cambrian Faunas, and the literature relating thereto, it has been 

 ascertained that Conocephalites as a generic name will not stand, 

 but must give place to that of Ptychojmria, Corda. No one has 

 done more to clear up this point than have Messrs. F. B. Meek 

 and C. D. Walcott, the latter the energetic director of the U.S. 

 Geological Survey. 



It appears that Zenker, in 1833, proposed the name of 

 Conocephalus for a blind Trilobite, previously known as Trilobites 

 Suheri, Schlottheim, and in 1839 Emmrich added a second 

 species termed Conocephalus strHatus, but possessing eyes. The 

 incongruity of this appears to have struck Corda, who in 1847 

 pointed out that Conocephalus was, at the time of its enunciation, 

 by Zenker, a preoccupied name, and proposed to substitute for 

 the blind Conocephalus {C. Sidzeri) the name of Conocoryphe, 

 and for the species provided with eyes {Conocephalus striatus) 

 that of Ftychoparia. Subsequently the illustrious palo3ontologist 

 Barrande, without separating the two forms, endeavoured to 



* Geol. Mag., 1884, I. (3), p. 343. 



t Trans. R. Soe. S. Austr., 1892, XV., PI. IL, p. 18: 



