Observations sur l espece Cosmogneta kargi Grandjean 1963: la protonymphe et la tritonymphe. Complements a l etude du gnathosoma. A couple of immature stases (protonymph and tritonymph) of the species Cosmogneta kargi known only in the adult stase, are discribed. A study about the gnathosoma of the adult and its development is achieved. A case of stenarthry quite particular and exeptional in the infracapitul of a tritonymph is expounded. This discovery states important problems of an ontogenetic and phylogenetic nature.