the cgg-cascs and early stages of some OassieHiLr. 7 



of the remarkable form it possesses in A. teeta, ditferiug 

 indeed very little from the other membranes : of these 

 there are only eight or ten used in the formation of the 

 complete ootheca. There are no marginal cells and each 

 membrane extends the whole width of the ootheca. 

 There are spaces for about 14 eggs in a case, and the eggs 

 are rather irregularly placed, so that the cells are also 

 irregular. After the eggs have been laid only about two 

 membranes are laid free on them : as these free membranes 

 can be easily turned back their form can be readily seen. 

 Tliis ootheca on account of its comparative simplicity is a 

 very instructive one. 



4. A. tigriiia. 



PI. ir, figs. 12, 13. 



The ootheca (figs. 12, 13) is in general similar to that of 

 A. conjinis ; it differs in several unimportant details and 

 in one very interesting point, viz. that the membranes 

 project much at the sides, and thus exhibit a very 

 irregular set of marginal spaces. The membranes appear 

 to be — notwithstanding the considerable width of the 

 ootheca — each not very broad ; the width of the case and 

 the considerable projections of the membranes laterally is 

 apparently due simply to the fact that one membrane is 

 laid a good deal to one side of the middle line, another 

 membrane much to the other side, and so on ; by this 

 means the case can be made to be in some places nearly 

 twice the width of a single membrane. 



5. Basipta stolida. 



PI. II, figs. 14, 15, 16. 



The ootheca of this species is a remarkable structure 

 totally different in plan (using the word in our interpreta- 

 tive fashion) and mode of execution from those previously 

 described. The ootheca is occasionally attached to the 

 surface of the leaf of the food-plant — Bracliyhvna eliscolor 

 — but much more frequently it is attached to the stem 

 and built around this, so as to form a very convex body, 

 somewhat like a sphere of which about one-third has been 

 cut away. It is formed of very delicate membranes. The 

 cells, some twenty or thirty in number, are placed so that 

 there is no membrane intervening between the leaf-surface, 

 or twig-surface, and the membranes that form the first 



