A review of described Metacyrba, the status of Parkella, and notes on Platycryptus and Balmaceda : with a comparison of the genera (Araneae: Salticidae: Marpissinae)

Parkella Chickering 1946 = Metacyrba F. O. P.-Cambridge 1901, n. syn.; Parkella venusta Chickering 1946 = Metacyrba venusta (Chickering 1946), n. comb.; Parkella fusca Chickering 1946 and Dendryphantes franganilloi Caporiacco 1955 = Metacyrba venusta (Chickering 1946), n. syn. The six valid described species of Metacyrba are diagnosed and re-illustrated to show previously unrecognized genitalic differences. Metacyrba similis Banks 1904 is resurrected as a subspecies, becoming Metacyrba taeniola similis Banks 1904, n. status. The female of Metacyrba pictipes Banks 1903 is described for the first time. Metacyrba arizonensis Barnes 1958 = Platycryptus arizonensis (Barnes 1958), n. comb., and Marpissa magna (Peckham & Peckham 1894) = Platycryptus magnus (Peckham & Peckham 1894), n. comb. Platycryptus broadwayi (Peckham & Peckham 1894) = Platycryptus magnus (Peckham & Peckham 1894), n. syn. [lectotypes and paralectotypes are designated for both names]. Metacyrba nigrosecta (Mello-Leitão 1945) = Balmaceda nigrosecta Mello-Leitão 1945, comb. restored. The genera Balmaceda Peckham & Peckham 1894, Metacyrba, and Platycryptus Hill 1979 are compared morphologically among themselves and to Breda Peckham & Peckham 1894 and Fuentes Peckham & Peckham 1894. The distributions of Balmaceda picta Peckham & Peckham 1894 and Metacyrba species are updated. Marpissa melanura F.O.P.-Cambridge 1901 is resurrected; it is not a synonym of Marpissa minor F.O.P.-Cambridge 1901 nor Platycryptus californicus (Peckham & Peckham 1888)

A review of the Nearctic jumping spiders (Araneae: Salticidae) of the subfamily Euophryinae north of Mexico

The generic and specific composition ofthe Nearctic jumping spiders ofthe subfamily Euophryinae north of Mexico is reviewed, and the biogeographic affinities of the constituent groups are diagnosed. The five North American species of HabrocestUln are removed from that non-euophryine genus; four are placed in the New Genus Naphrys, type species Habrocestum acerbum Peckham & Peckham 1909, creating the following New Combinations: Naphrys acerba (Peckham & Peckham), Naphrys bufoides (Chamberlin & Ivie 1944), Naphrys pulex (Hentz 1846), and Naphrys xerophila (Richman 1981). The fifth species is not an euophryine, and becomes Chinattus parvulus (Banks 1895), New Combination. Four species placed in the genus Tylogonus, another non-euophryine genus, are removed to the New Genus Mexigonus, type species Sidusa minuta F.O.P.-Cambridge 1901, creating the following New Combinations: Mexigonus arizonensis (Banks 1904), Mexigonus dentichelis (F.O.P.-Cambridge 1901),Mexigonus minutus (F.O.P.-Cambridge), and Mexigonus morosus (Peckham & Peckham 1888). One of the two species of Nearctic Euophrys has been misplaced, and becomes Chalcoscirtus diminutus (Banks 1896), New Combination. New state records are reported for Chalcoscirtus diminutus [Kansas, Michigan, Minnesota, Missouri, Nebraska, New Mexico], Mexigonus minutus [California], Naphrys acerba [New Mexico], and Pseudeuophrys erratica (Walckenaer 1826) [New York]. Of the eight known euophryine genera with Nearctic representatives, Anasaitis (one species) and Cory thalia (two species) are considered Neotropical in origin, whereas Chalcoscirtus (three species), Ezwphrys (one species), and Talavera (one species) are considered Holarctic. The Palaearctic Pseudeuophrys erratica is introduced. The affinities of the apparently endemic Nearctic Naphrys (four species) and Mexigonus (four species) are uncertain at this time. Although not an euophryine, the presence of a species of Chinattus in eastern North America is biogeographically interesting, as the other species in the genus are Asian; it joins a diversity of taxa with this distribution

A synonym in the genus Fluda (Araneae: Salticidae)

A synonym in the genus Fluda (Araneae: Salticidae

A new species of Neonella (Araneae: Salticidae) from southeast Florida

A new species of Neonella is described that has a distribution apparently restricted to the southeast coast of Florida. So far, it has only been found in Brevard and Monroe counties. It is closely related to N. mayaguez Galiano from Puerto Rico

Cory thalia canosa (Araneae: Salticidae) reassigned to Anasaitis

Four species of Cory thalia C.L.Koch 1851 were reported by Richman & Cutler (1978) to occur in North America north of Mexico. Subsequently, one of these four species, C. delicatula Gertsch & Mulaik 1936, was synonymized with Euophrys dim in uta (Banks 1896) (Edwards 1980). Of the three remaining species, only two species can validly be placed in the genus. These are C. conspecta (Peckham & Peckham 1896) and C. opima (Peckham & Peckham 1885), the northernmost species in the genus, both with reported distributions ranging from Central America to Arizona

Real-time flutter analysis of an active flutter-suppression system on a remotely piloted research aircraft

Flight flutter-test results of the first aeroelastic research wing (ARW-1) of NASA's drones for aerodynamic and structural testing program are presented. The flight-test operation and the implementation of the active flutter-suppression system are described as well as the software techniques used to obtain real-time damping estimates and the actual flutter testing procedure. Real-time analysis of fast-frequency aileron excitation sweeps provided reliable damping estimates. The open-loop flutter boundary was well defined at two altitudes; a maximum Mach number of 0.91 was obtained. Both open-loop and closed-loop data were of exceptionally high quality. Although the flutter-suppression system provided augmented damping at speeds below the flutter boundary, an error in the implementation of the system resulted in the system being less stable than predicted. The vehicle encountered system-on flutter shortly after crossing the open-loop flutter boundary on the third flight and was lost. The aircraft was rebuilt. Changes made in real-time test techniques are included