PRELIMINARY NOTICE. 



The late Mr. J. W. Salter, in Part I of his ' Monograph of British Trilobites ' 

 (p. 2, Pal. Soc, 1864), gave a preliminary classification of Trilobites, in which he 

 placed under the Peoetid^ the following genera : — Phillipsia, Griffithidbs, 

 Brachymetopus, Proetus, and Phaeton\ and in a " Notice to Correspondents " 

 (facing p. 177 of his last Part, IV, 1867) he expressed an opinion that " it would 

 be in some respects advisable to go on (in Part V) with the highest and most 

 compact group of the smooth-eyed Trilobites, viz. the PROETiDiE." Unhappily 

 his labours were brought to a close by death, and I have taken up the unfinished 

 narrative. 



After much hesitation, it seemed most convenient to commence with the 

 Trilobites of the Carboniferous Limestone, because, with the exception of the 

 genus Proetus^ they form a group by themselves which are only to be met with in 

 one formation and in a limited area, at least in this country ; and they also very 

 greatly needed to be re-examined and carefully figured. 



HENRY WOODWARD. 



British Museum (Natural History), 



Cromwell Koad, London, S.W. ; 

 August 20th, 1883. 



^ Made a synonym of the genus Proetus, by its author Barrande. 



