ANATOMY OF MARELLIA REMIPES — CARBONELL 8/ 



directly underneath them. On their ventral surface, the third valvulae 

 have a row of strong, long bristles that curve rearward (figured only 

 in fig. 17 B). 



These upper valves have been variously qualified as "feeble" (Uva- 

 rov, 1929) and "atrophic" (Rosas-Costa, 1940). They appear indeed 

 feeble if compared with the strong upper valves of the usual acridoid 

 ovipositor. When seen in its entire length (fig. 17 B, C 3VI), how- 

 ever, they are not suggestive of atrophy or disuse. They are indeed 

 strongly modified in relation to an unusual mode of oviposition, but 

 they look like perfectly functional organs. 



On the floor of the depression of the subgenital plate that harbors 

 the ovipositor, there is a well-developed egs^ guide (fig. 17 C, eg) 

 which intervenes between the first valvulae. 



The genital chamber (fig. 17 C, GC) is elongated and shows on its 

 roof the opening of a large spermatheca (Spt), and the gonophore on 

 the floor (Gpr). 



VIII. THE EGG rOD 



The egg pods of Marellia reniipes have been found and described by 

 the writer (Carbonell, 1957). They represent perhaps the most un- 

 usual type of egg pod found in any grasshopper, on account of their 

 shape and the fact that they are laid under water, adhering to the 

 undersurface of the floating leaves of the host plant. Another very 

 unusual type of acridoid egg pod has been recently described in Argen- 

 tina (Rosas-Costa, 1950 ; Liebermann, 1951). It pertains to the grass- 

 hopper Scotussa cliens (Stal). As that of Marellia, the egg pod of 

 Scotussa is epiphytic, being deposited by the insect on the upper sur- 

 face of the leaves of umbelliferous plants of the genus Eryngiiim. 

 But the egg pod of Scotussa is in every other respect entirely diflfer- 

 ent from that of Marellia, being shaped like a mantid ootheca and is 

 aerial instead of subaquatic. 



The egg pod or ootheca of Marellia remipes (fig. 18) has the gen- 

 eral shape of an inverted pyramid and adheres by its flat, basal upper 

 surface to the underside of the floating leaves of the host plant. It is, 

 hence, entirely submerged under water, and its only possible communi- 

 cation with the atmospheric air would be through the leaf itself, which 

 has on its inferior face a layer of aerenchyma. The apical or inferior 

 end of the egg pod has the form of a blunt, somewhat curved lobe (h). 



The study of a considerable number of egg pods has shown that, 

 though they are somewhat variable in size and shape, they have a re- 

 markably uniform organization. They present invariably a slightly 

 concave anterior or frontal surface with raised lateral edges, which 



