Page:The Habitat of the Eurypterida.djvu/40

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THE HABITAT OF THE EURYPTERIDA

SOUTH AMERICA

Carbonic. Coal Measures of Brazil. David White described some fragments from the Santa Catharina system, about 55 meters above the granite floor (Tubarão series) or 225 meters below the Iraty black shale (Passa Dois series) northeast of Minas, Santa Catharina, Brazil (297, 229, 589, 605). The fragments are of most doubtful identification, some being apparently plant remains, but others having a suggestion of relation to the Eurypterida (297, pl. XI, figs. 4, 6, 7, 8). These are described as Hastimima whitei White.


AFRICA

Devonic. Witteberg series. From the Upper Devonic Witteberg series of Cape Colony, South Africa, Professor A. C. Seward has described two fragments of a fossil which he considers to be a eurypterid. He compared it with the species described by David White from Brazil and called it Hastimima sp., saying: "The view which seems to me most hopeful is that this fossil represents part of a bodysegment of a Eurypterid" (262, 485). Seward sent the specimens to Woodward who not only concurred in the opinion as to the eurypterid nature of the remains, but he also considers that the Brazilian forms are eurypterids (325, 486). It is gratifying to note that the opinion expressed by these earlier writers is fully supported by Clarke and Ruedemann in their monograph where they have discussed this genus (39, 400–406) and figured some more of the fragments from Brazil.

The Witteberg series consists of a hard blue micaceous quartzite, replaced in some localities by shale or slate. So far as known it is unfossiliferous except for occasional plant stems allied to Lepidodendron and the widespread markings known as Spirophyton caudagalli. A photograph of this fossil given by Hatch and Corstorphine in their Geology of South Africa (111, fig. 22.) reveals no essential difference between it and the Spirophyton caudagalli of the Esopus, Oriskany and Hamilton of eastern North America. Seward considers that it is an inorganic structure and Grabau has gone even further in suggesting that it is due to the blowing back and forth of reed-like plants on a plastic surface capable of holding such markings long enough until covered over by wind-blown dust or sand. At any rate, the formation is undoubtedly non-marine, and the two eurypterid fragments therein could hardly have come from any other source than the land waters.