Woodward gave them a graceful backward curvature. Schmidt again drew them nearly straight.
A perusal of the literature suggests that this conception of the manyjointed composition of the chelicerae is based on doubtful evidence. Woodward, for example, says of P. anglicus [p. 37] that "three joints at least may be observed " and of P. bilobus [p. 57] "there appear to be five joints in the antennae of this species, but it is seldom that their true line of articulation can be readily distinguished. Five are clearly to be seen in one of the antennae figured in the accompanying woodcut, figure 10." Schmidt states [p. 74] "Von den Scheerenfühlern sind in meinem Material nur die letzten beiden eigentlichen Scheerenglieder vorhanden, die ersten Glieder, von denen 3–5 angenommen werden, fehlen uns bisher." Laurie [p. 516] concluded that the question of the number of segments is still unsettled, and that the markings resembling articulations on the proximal portion may be due to crumplings of the undoubtedly thin cuticle, adding: "I believe them to have consisted of three segments—a long straight proximal one, and the two distal ones which possess the toothed pincers."
Laurie's contention is corroborated by our examples of P. macrophthalmus and buffaloensis and its correctness is suggested by the rigidly straight direction of the chelicerae in both the European and American species which can only mean the lack of articulation in the long arms. Finally we have also been able to convince ourselves of the presence of but three articulations in a fine specimen of one of the principal English species, P. bilobus, in the possession of the American Museum of Natural History. In this specimen both chelicerae show long straight well preserved basal segments without any trace of articulation in them, the whole chelicera being distinctly composed of but three segments.
Another problem in regard to the chelicerae of Pterygotus not yet solved by direct observation is their point and mode of attachment to the cephalothorax. A glance at the restorations of P. anglicus by Woodward, and P. osiliensis by Schmidt; both reproduced in
