The Lampropidae (Crustacea: Cumacea) of the World Author Gerken, Sarah text Zootaxa 2018 2018-06-01 4428 1 1 192 journal article 22652 10.11646/zootaxa.4428.1.1 e10e53f2-0e1b-46f6-8b0f-af19d5529711 1175-5326 3769771 2419A7F0-5AED-47EC-86BB-06AADB2A4BD9 Pseudodiastylis Calman, 1905 Pseudodiastylis Calman, 1905: 1 , 16. Type species. Pseudodiastylis ferox Calman, 1905 , by monotypy. Diagnosis. Carapace not dorsoventrally flattened, marginal carina absent, eyelobe present, pseudorostral lobes long or short, acute. Antennule flagella unequal, accessory flagellum much less than 0.5 length of article 1 of main flagellum. Mandible navicular. Maxillule palp absent. Pereopod 1 slender. Pereopod 5 longer than pereopod 4 basis. Telson long, at least 0.9 uropod peduncle length, with post–anal constriction. Uropod endopod of 2 articles. Uropod exopod article 1 0.5 length of article 2. Female with fully developed exopod on pereopod 2, rudimentary exopods on pereopods 3–4, without pleopods. Male with antenna unknown, without penial lobes, with 3 pairs of pleopods. Species. Pseudodiastylis benthedii Ledoyer, 1988 , P. delamarei Reyss, 1975 , P. ferox Calman, 1905 . Remarks. Within the Lampropidae , this genus is unusual in having a very short accessory flagellum. The only other genus with a short accessory flagellum is Austrolamprops , in which the accessory flagellum is greater than 0.5 the length of the first article of the main flagellum. In Pseudodiastylis the accessory flagellum is minute, much less than 0.5 the length of the main flagellum.