OGYGIA BUCHII. 



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Sub-species I. 

 Ogygia angustissima, n. sp. PI. XTV, figs. 8, 9. 



0. ovata, antice obtusa, parva, 17 lineas longa, 13 lata, capite transverso, axe angus- 

 tissimo. Omnino 0. Buchii simillima, nisi glabella tertiam partem latitudinis gencB vix 

 efficiente ; margine antico capitis obtuso truncato : axe thoracis caudcpque pleuris ter 

 angustiore. 



I cannot believe this to be a mere variety of 0. Buchii, though it does approach very 

 near in character to young male specimens of that species. 0. angustissima has so extremely 

 narrow an axis, and so broad, transverse, and truncate a head, that, whatever may have 

 been the ' origin of the species,' there is sufficient difference in this to afford us a good 

 diagnosis. The specimens are in the choice cabinet of Mr. Griffith, Davies, of 17, Cloudesley 

 Street, Islington. 



Locality. — Llandeilo Flags. Gilwern, near Llandrindrod,, Builth. 



To show how these Llandeilo trilobites are occasionally maltreated by cleavage, I 

 give "a woodcut from a specimen of 0. Buchii in Mr. Henry Hicks' cabinet. It was 

 found at the east end of the section of vertical slate-rocks in Abereiddy Bay, Cardigan- 



FiG. 30. 



Ogygia Buchii, distorted by cleavage ; from the vertical black slates of Abereiddy Bay, Cardigansliire. 



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