[Embryonic and postembryonic development of Cucullanus cirratus Müller, 1777 (Nematoda, Cucullanidae)].

Embryonal development of C. cirratus is described for the first time. The cortical activity at the first stages of cleavage has been noted. The extrusion of one of thdiate type, however there are some peculiarities. At first, the blastopore has a slit-like form, then closes in the middle and thus two openings are formed. The "tadpole" embryo appears in 3--4 days. Hatching of the first stage larvae take place on the 10-th--12-th day after the cleavage starts. The description of it is given. The moulting occurs in water. The description of the second stage larva is also given.