The subgenus Svenax is a contraction of Sven Axel, the given names of the paleontologist :sv:Sven Axel Tullberg|Tullberg.
Taxonomy
Position of ''Peronopsis palmadon''
Peronopsis palmadon is intermediate between Peronopsidae and Condylopygidae, but it is not clear whether P. palmadon is ancestral to the Condylopigidae, a condylopigid exhibiting regression towards ancestral characters, or an example of parallel evolution.
P. amplaxis Robison, 1982 has been found in the Middle Cambrian of Central Asia and North America.
P. batenica Bognibova, 1971 occurs in the Middle Cambrian of the Russian Federation.
P. crassa Lermontova, 1940 is present in the Middle Cambrian of the Russian Federation.
P. deonsJell and Webbers, 1992 has been collected in the Middle Cambrian of Antarctica.
P. hypagnostiformis Bognibova, 1971 has been found in the Middle Cambrian of the Russian Federation.
P. inarmata Hutchinson, 1962 occurs in the Middle Cambrian of Newfoundland, Canada.
P. montis Matthew, 1889 is known from the Middle Cambrian of the Russian Federation, and Canada.
P. uzbekistanica Hajrullina, 1970 was excavated from the Middle Cambrian of Uzbekistan.
Subgenus ''Peronopsis (Proacadagnostus)''
P. normata synonym Diplorrhina normata is recorded from the Middle Cambrian of the Russian Federation, Scandinavia, England, Spain, China, and Australia.
Subgenus ''Peronopsis (Svenax)''
P. pusillus synonym Agnostus pusillus has been found in the Middle Cambrian of Australia and Sweden.
P. egenus is known from the Middle Cambrian of the Russian Federation, China, England and Greenland.
P. eoscutalis Hajrullina, 1970 occurs in the Middle Cambrian of Uzbekistan.
P. hartshillensis Kobayashi, 1939 has been deposited in the Middle Cambrian of England.
P. lingula synonym Svenax vafer, is present in the Middle Cambrian of Australia and Greenland.
P. matthewi Hutchinson, 1962 has been found in the Middle Cambrian of England and Canada.
P. scutalisHicks, 1872 synonyms Agnostus exaratus and A. scutalis, is known from the Middle Cambrian of the Russian Federation, Australia, Wales, Wales, Greenland, Canada, Sweden and Italy.
P. spitiensis has been collected from the Middle Cambrian of India.
Subgenus ''Peronopsis (Vulgagnostus)''
P. longinqua Öpik, 1979 has been excavated from the Middle Cambrian of Australia and the Russian Federation.
P. gedongensis Huang and Yuan, 1994 synonym P. pseudointerstrictus is recorded from the Middle Cambrian of China, Sweden and the Russian Federation.
P. prolixa occurs in the Middle Cambrian of Australia.
P. guoleensis Sun, 1989 is present in the Middle Cambrian of China.
P. taijiangensis is found in the Middle Cambrian of China and the Russian Federation.
