The Ufipa Flightless Forest Grasshopper was described in 1953, it is known only from the type specimen that had been collected in 1952 in a ravine with dense matted grass on the Ufipa Plateau ij southwestern Tanzania.
The species was not found since and might be extinct.
This species was described in 1984 based on specimens from Kettle- and Okanagan Valleys in British Columbia, Canada.
The species appears to be lost or even extinct, on the other hand it might not be valid after all but might turn out to be identical with the Red-shanked Grasshopper (Xanthippus corallipes (Haldeman)) (see photo).
 James W. Miskelly: Updated checklist of the Orthoptera of British Colombia. Journal of the Entomological Society of British Columbia 109: 24-29. 2012
The Pegasus Spur-throated Grasshopper was described in 1919, it was found on some small islands in the Okeefenokee Swamp in Georgia, where it inhabited dense thickets of vegetation.
The species is apparently very closely related to the Larger Fork-tail Grasshopper (Melanoplus furcatus Scudder), and was also assigned to that species as a subspecies. It differs from this species by its more solid coloration and by the form of the male cerci.
 Morgan Hebard: New genera and species of Melanopli found within the United States (Orthoptera; Acrididae). Transactions of the American Entomological Society 44: 141-169. 1918
The Rocky Mountain Locust inhabited a large range., including Alberta, Manitoba, and Saskatchewan in Canada and Arizona, Colorado, Iowa, Kansas, Minnesota, Montana, Nebraska, North Dakota, Texas, and Wyoming in the USA.
The full-grown adults reached lengths of about 3 cm.
The species formerly formed seasonally swarms of giant sizes, which then devastated large areas of North America, destroying countless crops, and causing famines.
It is said that the locust plague did not spared cotton clothing or leather when found, and it is furthermore claimed, that they may have even eaten wooden fencing posts.
These last assertions, however, are probably pure fantasy.
The last large swarms were recorded in the years between 1873 and 1877, the last specimens were finally collected in Manitoba, Canada in 1902.
The reasons for the extinction of this once so common species are not well known, but it has been argued that plowing and irrigation by settlers in the Great Plains disrupted their natural life cycle in the areas they lived in, so it is reported that farmers destroyed over 150 egg cases per square inch while plowing, harrowing or flooding. 
 Jeffrey A. Lockwood: Locust: The Devastating Rise and Mysterious Disappearance of the Insect that Shaped the American Frontier. New York: Basic Books 2004
The Ogasawara Grasshopper was described in 2003 based on three specimens, two males that had been collected in 1984 on the island of Hahajima and that were found in the collections of the Laboratory of Systematic Entomology in Sapporo, as well a female lacking any data except for ‘Ogasawara’ found in the National Institute for Agro-Environmental Sciences in Tsukuba, Japan.
The species is quite large and was uniformly green colored in life (faded to yellowish brown after death).
The Ogasawara Grasshopper was never recorded alive and was never found since its description, thus it is believed that the species is most likely extinct. 
 Gen Ito: Ogasawaracris gloriosus, a new genus and species of possibly extinct grasshopper (Orthoptera: Acrididae) from the Ogasawara Islands. Entomological Science 6: 85-88.2003
This, indeed wingless and therefore flightless, predominantly brown colored grasshopper species was described in the year 1909.
The males reached a length of 1,72 cm, the females of 2,45 cm.
The species is considered extinct nowadays, for what introduced Norway (Rattus norvegicus (Berkenhout)) and Black Rats (Rattus rattus (L.)) are held responsible for.
 J. A. G. Rehn: A new species of the genus Paroxya from Bermuda (Orthoptera). Entomological news, and proceedings of the Entomological Section of the Academy of Natural Sciences of Philadelphia 20: 343-345. 1909
This species was described in 1919, apparently from a single female specimen.
The Piute Band-winged Grasshopper was found near Mason, Lyon County in the desert of Nevada, USA.
The species was probably closely related to the Delicate Grasshopper (Derotmema delicatulum Scudder), from which it differed by its more robust form, its broader head and other characters. 
The Piute Band-winged Grasshopper is now considered possibly extinct, without any significant reasons known therefor.
 James A. G. Rehn: Descriptions of new and critical notes upon previously known forms of North American Oedipodinae (Orthoptera; Acrididae). Transactions of the American Entomological Society 45: 229-255. 1919