1925] A Specimen of Melanoplus differ entialis Thomas 287 
the study of external anatomy, and which were of uncertain 
origin. Because of the lack of suitable preservation, no attempt 
was made to study the structure of the median ocellar nerve. 
Instead, the specimen was preserved intact, and will be placed in 
the type series of the insect collections at the University of Illinois, 
where it can be studied further by anyone to whose work such a 
study may be relevant. 
Fig. 1. Melanoplus differ entialis with four ocelli, anterior view of head. 
This particular malformation appears to be exceedingly rare 
among insects. The only other examples known to the writer are 
a specimen of the common meadow grasshopper, Melanoplus 
femur-ruhrum Riley, described by M. W. Blackman, 3 and a spe- 
cimen of a saw-fly, T enthredella simirubra Norton, described by 
M. T. Smulyan. 4 In Blackman’s specimen the median ocellus 
was replaced by a second pair of ocelli in a manner almost iden- 
tical with the example here reported. 
3 Blackman, M. W., Psyche, v. 19, 1912, pp. 92-96, 1 fig. 
4 Smulyan, M. T., Proc. Bost. Soc. Nat. Hist., v. 36, 1923, p. 401. 
