Dolichopterus macrochirus Hall
Plate 35, figure 1; plates 40–45
Dolichopterus macrocheirus Hall. Palaeontology of New York. 1859. 3:414, pl. 83, fig. 1; pl. 83A, fig. 1
Professor Hall based his description of this genus Dolichopterus and of its genotype D. macrochirus upon a single specimen from the waterlime at Williamsville. This is now in the American Museum of Natural History and is unique in its state of preservation, for it can be lifted bodily out of the matrix and exhibits both sides; these were so accurately figured by Whitfield that new figures can add only immaterial features. Unfortunately, however, this type lacks the greater part of the postabdomen and telson and retains only the proximal portions of the limbs, save the last pair, besides being incomplete in such other important points as the posterior portion of the metastoma, the opercular appendages and the operculum itself. It is therefore extremely gratifying that later collections in this State have afforded three more specimens of this extremely rare species which happily supply the desired information. The most important of these is a specimen from the famous locality of Wheelock's hill, Litchfield [pl. 43]. This retains the postabdomen and telson and furnishes important information as to the limbs
genital appendages to Dolichopterus, pointing out its similarity to the corresponding part of D. macrochirus. The opercular appendages of Stylonurus however are not yet known and hence this similarity is not conclusive of identity with Dolichopterus.
Schmidt figured [op. cit. pl. 7, fig. 9] a very interesting leg, referred by him with doubt to Pterygotus osiliensis, and which possesses broad, leaflike spines like those on the last legs of species of Dolichopterus. Holm [p. 56] indicated the similarity of this leg to that of Dolichopterus but suggested that the broad spines are only wrinkles since the limb is very poorly preserved. From our observations of like appendages on the legs of at least two species of Dolichopterus, we consider it probable that Schmidt's figure is correct and that this leg indeed demonstrates the presence of the genus Dolichopterus in the fauna of Rootziküll.
