Two rcmarkaUc forms of Mcmtid oothccac. 511 



sections through the two oothecae, together with the 

 photographs, should make clear anything that is at all 

 obscure in the foregoing description. 



These two forms of Mantid oothecae differ radically from 

 all those that have previously been described on account 

 of their hollow nature, whereby the enclosed mass of eggs 



Fig. 1. — Diagrammatic transverse Fig. 2. — Diagrammatic transverse 

 section of the ootheca from section of the ootheca from 



Delagoa Bay. the Andes. 



Fig. 3. — Portion of the grooved ridge of the Delagoa Bay 

 ootheca viewed from above. 



is surrounded by an empty air-space. Thanks to the 

 admirable researches of Giardina * we are acquainted with 

 the structure and method of formation of the ootheca of 

 the European Mantis, 31. rdigiosa. In this species — and 

 it is probable that in nearly all the Mantinac the structure 

 of the ootheca is essentially similar — the eggs are enclosed 

 in a double series of thin-walled cells ; the cells, except a 

 few at the anterior and posterior ends of the ootheca, are 

 practically divided into an internal and an external half ; 

 the former contain the eggs, the latter are empty and 

 together form a thick spongy layer protecting the inner 

 core of eggs. Each egg-cell communicates with the 

 exterior by a narrow passage, opening on the upper surface 



* Natural. Siciliano (N.S.), Anno II, and Giorn. Soc. Sci.Nat.Econ. 

 Palermo, XXII (1899). 



