90 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I37 



the actual laying of the eggs. The series of eggs would be deposited 

 in this way from the upper part downward to the apex. After the 

 eggs are laid, the emission of the frothy cemental secretion continues 

 for a while, and the apical pointed lobe of the egg pod is built, its par- 

 ticular structure being shaped after the end of the female abdomen, 

 the lateral frontal processes (/, /) corresponding to the cerci, and the 

 front median process (i) being a mark left by the median excision of 

 the subgenital plate. 



If we observe the egg pod from its lateral surface (fig. i8 A), its 

 whole form and pattern is suggestive of the described mode of ovi- 

 position. We must observe that according to tliis explanation, the 

 abdomen would be at the beginning of the oviposition nearly hori- 

 zontal and parallel to the leaf surface. As the oviposition proceeds, it 

 would describe an arc by pivoting on its base, its distal part being at 

 last at an angle with its first position. The somewhat arched shape 

 of the egg pod and the fanlike pattern of its lateral walls support this 

 explanation. The inclination of the frontal surface of its apical lobe, 

 as seen from the side, would mark the final inclination of the female 

 abdomen. We must remark, by the way, that this final position of the 

 abdomen is the same as that shown by the usual ground-laying grass- 

 hoppers during oviposition. The following facts, in the writer's 

 opinion, further support his explanation. 



a. The location of the ovipositor in a cavity formed by a large sub- 

 genital plate makes its situation adequate for attaching the egg pod 

 to the undersurface of the leaves when the insect is in the normal 

 resting position and the abdomen horizontally extended. 



b. The location of the egg pods, always near the edges of the leaves, 

 and their orientation with the frontal or opercular surface toward the 

 leaf edge, is also in favor of the said mode of egg laying. So is the 

 position of the cephalic pole of the embryo, which in other grasshop- 

 per egg pods points to the side where the egg-laying female is during 

 oviposition. 



c. If we apply the end of the abdomen of a female of Marcllia to 

 the frontal area of the apical lobe of an egg pod in such a way that 

 the upper surface of the subgenital plate lies against it, there can be 

 observed a perfect coincidence of their different parts. The median 

 frontal process of the apical lobe of the egg pod (fig. i8, i) fits into 

 the terminal emargination of the subgenital plate (see fig. i6 B) ; the 

 lateral frontal processes of the egg pod (fig. i8, /, /) closely embrace 

 the abdominal end at the level of the cerci, and the excavated tri- 

 angular area delimited by the bases of the three mentioned processes 



