GENERAL REMARKS. 173 



Family Bronteid.*:. Bronteus andersoni, Eth. and Nich. 



Family Acidaspid^e. Acidaspis barrandei, Fletch. and Salt. 



Family Encrinurid^e. Encri nurus punctatus (Briinn.), var. calcareus. 



Family Calymenid;e. Calymene blumenbachi, Brong. 



Family Cheirurid.e. Clieirurus (Younyia) trispinosus, Young. 



Family Phacopidje. Phacojjs (Phacopidella) elegans (Sars and Boeck). 



Bargany Group. 

 Family Encrinurid.*;. Encrinurus punctatus (Briinn.), var. calcareus. 



Wenlock Group. 



Family LichadidvE. Liclias (Corydocephalus) anglicus, Beyr. 



Family Encrinurid^e. Encrinurus punctatus (Briinn.), var. calcareus. 



Family Phacopid.e. ? Phacops (Phacopidella) downinguv, Mureh. 



general remarks. 



The trilobitic fauna of the Lower Paleozoic beds of the Girvan area shows 

 certain marked characteristics which call for notice. Firstly, there is the occurrence 

 of certain peculiar genera or subgenera known at present from no other region. 

 Such are Bronteopsis and Teratorhynchus. Secondly, some of the genera and sub- 

 genera are not found elsewhere in the British Isles, though occurring in other parts 

 of the world. The Bohemian genera Telephus, Bohemilla, and Arethusina are 

 included in this category, and the North European subgenera Nieszlcowsl-ia and 

 Younyia. Thirdly, there are several generic constituents which, though not 

 unknown from other Lower Paleozoic regions in the British Isles, are decidedly 

 uncommon and rare; such are Apatokephalus, Diomde, Salteria, Tornquistia, 

 Dindymene, and Sphseroconjplte. We may further note the unusual stratigraphical 

 horizons at which certain of the genera occur. Thus Shumardia and Triarthrus 

 occur here higher than is typically the case, while Arethusina and Tornquistia 

 are represented at an earlier stage than usual. 



The occurrence of some forms identical with foreign and not British species is 

 likewise remarkable {e.g. Agnostus perrugatus, Gyclopyge armata, etc.), while others 

 are less allied to members of English Palaeozoic faunas than to members of conti- 

 nental faunas. It is thus seen that the Girvan trilobitic fauna is composed of sever al 

 diverse elements. 



Local Species. — The large proportion of species peculiar to the locality first 

 attracts our attention; even omitting doubtful or indeterminable species and 



