FOSSIL FLORA OF THE STAFFORDSHIRE COAL FIELDS. 165 



Trigonocarpus sp. 



Remarks. — Several specimens of Trigonocarpus have occurred at the following 

 localities, but were not in a good state of preservation for a satisfactory determination, 

 though specifically distinct from that mentioned above. 

 Horizons and Localities. — 



Ten-foot Ironstone Measures : Ettingshall. 

 Immediately below Bottom Coal : Ruiton, near Sedgley. 



Hexagonocarpus Renault. 



1890. Hexagonocarpus, Renault, Flore foss. ten: houil. de Gommentry, deux, part, p. 649. 



Description. — Seeds elongated, hexagonal in transverse section, and prolonged at 

 the angles into six more or less prominent wings. 



Remarks. — These seeds are most frequently represented by casts of the cavity 

 originally surrounded by the sclerotesta, and which in section show a corresponding 

 number of ridges to that of the wings. 



Hexagonocarpus is distinguished from Trigonocarpus in having six equally 

 prominent ribs on the " nut " and in the base of the seed ending in a hexagonal flattened 

 cone caused by the six ribs extending over its surface and meeting in the centre. 



In Trigonocarpus there are three prominent and three faint ridges, the latter often 

 scarcely visible, and the nut has more a circular than a hexagonal form in transverse 

 section. The ribs also do not extend over the base, which is generally bluntly rounded. 



Well-preserved specimens of Hexagonocarpus are very easily distinguished from 

 Trigonocarpus, especially when the nut is free from the matrix or the base exhibited ; 

 but, if badly preserved and partially embedded in the matrix, they might easily be 

 mistaken for Trigonocarpus. 



The genus Hexagonocarpus does not appear to be common in British Carboniferous 

 rocks, though more than one species is known to occur. 



Hexagonocarpus Hookeri Kidston, n. sp. 



1848. Hooker, "On the Structure and Affinities of Lepidostrobus," Mem. Geol. Survey of Great Britain, 

 vol. ii. part ii. p. 456, fig. 5. 



Description. — Nucule 6*50 mm. to 8 mm. long, gradually tapering to a pointed 

 apex, and terminating below in a short hexagonal cone. The sides have six equally 

 prominent ribs, which extend over the base and divide it into six triangular areas. 



Remarks. — The specimen figured by Hooker as a probable sporangium of 

 Lepidodendron elegans is evidently a small Hexagonocarpus. I have seen other 

 and better examples of " nuts " which are apparently referable to the same seed, from 

 Dove Cliff, near Barnsley, Yorkshire, collected by Mr W. Hemingway (Hor. Woolley 

 Edge Rock, Westphalian Series). These latter examples are free from the matrix, 



