57f,0C7J? Vol. 77, pp. 161-170 30 October 1964 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON A REVISED INTERPRETATION OF THE PRIMITIVE CENTIPEDE GENUS ARRUP, WITH REDESCRIPTION OF ITS TYPE-SPECIES AND LIST OF KNOWN SPECIES 1 ( Chilopoda : Geophilomorpha : Mecistocephalidae ) Ry R. E. Crabill, Jr. Smithsonian Institution, U.S. National Museum, Washington, D.C. In 1912 (p. 654), Chamberlin proposed a new genus and species, Arrup pylorus, creating for its reception a new family, Amrpidae. In 1920 (p. 184), he reduced Arrupidae to the rank of subfamily within Mecistocephalidae, where it properly re-mains today. This genus, represented apparently only by the original species, had long puzzled me. Quite clearly it seemed very similar to the eastern Asian Prolamnonyx, but according to the original description of Arrup, there was a major intra-generic difference between the two. In Prolamnonyx the first maxillary coxosternum is entirely without midlongitudinal di-vision, whereas according to Chamberlin's characterization of Arrup, the first maxillary coxosternum is distinctly suturate or divided midlongitudinally (see 1912: 667, Fig. D). The types could not be located, and until quite recently additional speci-mens of pylorus could not be found. Some years ago a Californian chilopod collection made by R. O. Schuster and L. M. Smith was generously placed in my hands by my friend and colleague, Dr. R. L. Hoffman. Re-cently, while continuing my perusal of this material, I un-expectedly came upon seven specimens of a genus that I unhesitatingly identified at first as Prolamnonyx. Generically they agree in every detail with all of the Prolamnonyx speci-1 This study was undertaken with the aid of a grant from the National Science Foundation. 17— Proc. Biol. Soc. Wash., Vol. 77, 1964 ( 161 ) SMITHSl nni INSTITUTION UU i> u IbC
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