Contribution aux mésostigmates d’Algérie (Parasitiformes: Liroaspidae, Veigaiidae). Liroaspis baloghi, а new species оf the Algiers аrеа, is intermediate between L. togatus (Koch) and Willmannia sejiformis Balogh. The morphological comparison оf these 3 species indicates that Willmannia Balogh, 1938 cannot be generically separate from Liroaspis Banks, I902. The presence оf seta bearing tubercles at the caudal margin is а generic -and even familial - feature; their degree оf development is а stage character. The variability of some other characters in consideration is either intrageneric оу too poorly known. The four developmental stages ауе described and figured. The mandibles оf this hemiedaphic species suggest omnivorous habits. Some data are given about the occurence оf members оf the genus Veigaia in north middle Algeria. Both sexes оf Cyrthydrolaelaps incisus var. jubae n. var. have Ьееn found in Posidonia, оп the sea shore, 70 km. Е. оf Algiers; they are briefly described and figured.