IN crayfish, as in related Crustacea, the eggs are carried fastened to the limbs of the abdomen during the long period of development that precedes their hatching. As the openings of the oviducts are upon the thorax, the eggs have to be transported some distance to reach the abdominal limbs. It is the purpose of this article to describe some of the activities of the female associated with the extrusion of eggs from the oviducts, their transportation to the limbs of the abdomen, and their fixation there. In a crayfish in France, a species of Astacus, some of the behavior of the female in laying was long since made out by Chantran (Compt. Rend. Acad. Sci. Paris, vol. 71, pp. 43-45, 1870; vol. 74, pp. 201-202, 1872) in his long continued and careful study of the life history of the crayfish. His too brief statements are as follows. The female crayfish stands up and for several hours secretes a viscid mucus from the limbs of the abdomen. It then lies down upon its back with the abdomen bent forward toward the openings of the oviducts, in such a way as to form a sort of chamber, in which, on the following night, the eggs were received as they were expelled from the reproductive organs. In different females the expulsion of eggs lasted from one to several hours. The eggs were plunged into the mucus which, as it were, bound the edges and the end of the abdomen to the thorax and also helped to make the boundary of the above mentioned chamber or basket. In this chamber there was some water as well as eggs and mucus. All the eggs were laid at one period and rarely were any laid in the day time. Observations upon the laying habits of an American crayfish, Cambarus affinis, as published in this journal (Amer. Nat., vol. 38, pp. 165-206, 1904) showed a close agreement with the above account. Renewed observations upon the same species in April, 1904, have added more details and verified suppositions previously made to bridge over gaps in observation of actual extrusion and transport of eggs.