106 
Psyche 
[September 
gynandromorph as well. The author wishes to thank Dr. 
Hill for the privilege of studying the grasshoppers loaned 
him. 
Melanoplus mexicanus phase spretus (Walsh) is re- 
garded by most entomologists as a phase of Melanoplus 
mexicanus mexicanus (Saussure) and is looked upon by 
most Orthopterists as the Rocky Mountain Locust which 
was so prevalent and destructive in the United States from 
1862 to 1876. 
The author of this paper described a gynandromorph of 
Melanoplus mexicanus mexicanus (Sauss.) 2 but this de- 
scription of the morphology is quite different from the 
description of the gynandromorph of M. m. mexicanus 
(Sauss.) Extreme Migratory Phase presently to be de- 
scribed. 
Description of the 
Gynandromorph of M. m. mexicanus (Sauss.) 
Extreme Migratory Phase. 
This gynandromorph is typically female in structure in- 
cluding the body morphology and the appendages except 
for the posterior end of the abdomen which is typically male 
in the left half and mostly typically female in the right half. 
The lateral carinae of the fastigium of the head, are 
not prominent and the fastigeal depression is shallow. 
These characters are typical of normal female specimens. 
The interocular space is wide as in normal female speci- 
mens. 
The tubercle on the mesosternum, which is very well 
developed in normal male specimens and only faintly in- 
dicated or entirely absent in normal females, is lacking 
in the gynandromorph. The femora and tibiae of the first 
two pairs of legs of the gynandromorph are less heavily 
constructed than in the normal males and in this respect 
resemble the femora and tibiae of typical females. The 
arolia of the tarsi of the gynandromorph are small and 
resemble those of a normal female. 
The left half of the posterior end of the abdomen is 
typically male in structure with very little distortion. The 
2 Severin, H. C. 1943. A Study of a Gynandromorph of Melanoplus 
mexicanus mexicanus (Sauss.) (Orthoptera) 1943. Journal of New York 
Entomological Society Vol. LI., pp 179-183. 
