THE LOWER PALEOZOIC TRILOBITES OF 

 THE GIRVAN DISTRICT, AYRSHIRE. 



SUPPLEMENT. 



INTRODUCTORY REMARKS. 



Ix the preparation of my Monograph of the Grirvan Trilobites, of which the 

 last part was published by the Palseontographical Society in 1906, all the material 

 which was then available in the various collections and museums was examined 

 and utilised. But since that date Mrs. Gray of Edinburgh has been able to collect 

 further specimens, amongst which are several new species, so that there is now 

 occasion for a supplement to that work. Some of the forms which were there 

 described from imperfect material are now better known, thus necessitating a 

 revision of the former specific determinations or diagnoses, and in other cases 

 allowing of the establishment of distinct new species. The number of trilobites 

 from the Grirvan area is accordingly increased by the addition of twenty-three new 

 species and of three new varieties. 



The following are lists (1) of the emendations necessary in the previous 

 Monograph, (2) of new horizons for previously described species, and (3) of the 

 stratigraphical distribution of the new species here described. 



The characters and afl&nities of the trilobitic fauna as a whole were sufficiently 

 described and discussed in my previous work, and the new material and facts do 

 not render necessary any modification of the general conclusions then reached 

 {op. cit., pt. iii, pp. 173-179). The individuality and local specific peculiarities of 

 the Girvan assemblage in Ordovician times mark it off sharply from that of other 

 British areas. 



(1) Emendations and Corrections. 



New designation or reference. Precious designation or reference. 



Trinucleiis albidus, sp. nov. Trinticleus sp. b. 



Ampyx macconochiei, Eth. & Nich. Trinucleus? macco» oc/tie «', Eth.&Nich, 



Bemopleurldes nicholsoni, sp. nov. Remopleurides colbii, Portl. 



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