An ultrastructural description of the egg of Anopheles (Anopheles) peryassui Dyar and Knab is given from material collected in Venezuela. The egg is remarkable in several respects. Its deck and frill, on the ventral surface, have been reduced to two small, oval, crownlike areas at the anterior and posterior ends. The remainder of the ventral surface and all the dorsal surface are covered by plastron-type chorionic cells, which on the ventral side are of an unusual type. The very long floats are positioned much more toward the dorsal surface than is usual in the Anopheline egg. They are extraordinarily modified anteriorly and posteriorly to form five to seven pairs of tubular, porous filaments, which are longest at the two ends of the egg. When eggs are oviposited on damp paper, the filaments lie flat along the egg's sides; immersion in water separates and spreads the filaments laterally. Almost all eggs float with the ventral side down, the reverse of the usual position for Anopheles.