CARADOOIAN CYSTIDEA FROM GURVAN. 



361 



1. 



Whitehouse Group. 

 Bicellograptus complanatus, 

 Pleurograptus linecms. 

 Ardwell Group. 

 Flagstones and shales, 

 Climacograptus caudatus. 

 Balclatchie Group. 

 Conglomerate, mudstones. 

 Climacograptus bicornis. 



Shalloch Mill, plates suggestive of 

 Echinoencrinus. 



Ardmillan, a Glyptocystid (? CJieiro- 

 crinus) and plates (a) and (/3). 



Balclatchie, plates {^) (7 = Glypto- 

 cystidean), and (e = Echinosphaerid.). 



Dow Hill, plates {8) and (e), plates of 

 Gheirocr. ? and fragments indett. 



The plates e from the Balclatchie conglomerate comprise those described and 

 roughly figured by Nicholson and Etheridge (1880, pi. 22, ff. 13-19). They belong 

 to some genus or genera of the Echinosphaeridae and, when thus interpreted, are not 

 specially remarkable. 



§ 5. The fragments from the Balclatchie, Whitehouse, Saugh Hill, and Camregan 

 Groups are not without interest, but to determine them more precisely would (assuming 

 it were at all possible) be a laborious task, adding nothing of moment to the geology of 

 the district or the palaeontology of the Cystidea. Their further study may well be 

 postponed till better material has been obtained. This memoir therefore deals only 

 with the extensive and interesting series from the Starfish Bed of Thraive Glen. 



§ 6. The position of the Starfish Bed in the Drummuck Group was defined by Prof. 

 C. Lapworth (1882, pp. 617, 621), from whose paper the following facts are abstracted. 

 Longer lists of fossils, which have, however, to be used with caution, are given by 

 Peach & Horne (1899, p. 524). 



Purple Conglomerate of Mulloch Hill, 



Base of Llandovery. 



" The grandest palaeontological break in the entire Girvan succession." 



Top of Caradocian [in this region]. 

 Drummuck Group, 400 feet. 



Upper Mudstones : soft, blue, homogeneous, thick-bedded, concretionary in parts, 

 iron-stained : Fossils rare. 



Starfish Bed : a hard, greenish-grey sandstone,a few inches thick,highly calcareous: 

 almost made up of Fossil remains, Tetraster Wyville-Thomsoni, Trinucleus 

 Buchlandi, Staurocephalus globiceps, Plectamhonites sericea, Strophomena 

 grandis. Cowper Reed (1903-1906) adds Agnostus agnostiformis, Phillip- 

 sinella parabola, Illaenus Bowmanni var. longicapitatus, and several new 

 species. 



