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\\t Cait.itlt.in |Iitt0ttiol(i0bt, 



Vol. XXXVII. LONDON, APRIL, 1905. No. 4 



NOTES ON THE LOCUSTID^ OF ONTARIO. 



BY E. M. WALKER, B. A., M. B., TORONTO . 



(Continued from p. 38.) 

 Sub-family DECTICIN^. 



22. Atlanticus pachymerus, Burm. — The Shield-back Grasshopper. 



Dedicus pachymerus, Burm., Handb. der Ent., II., 1838, 712. 



Thyreonotus pachymerus, Scudd., Bost. Journ. Nat. Hist., VII., 

 1862, 453. 



Atlanticus pachymerus, Scudd., Can. Ent., XXVI., 1894, 179. 



Measurements: Length of body, $ 17-23 mm., 9 20-22 mm.; 

 of pronotum, $ 8.8-9.3 "ini., 9 8.5-9 mm.; of hind femora, -^ 

 16 mm., 9 16.5 mm.; of tegmina, $ 7-3-8 mm.; of ovipositor, 

 1 8.3-1 9 mm. 



This large brown insect, the " Shield-back Grasshopper," is readily 

 known from all others in our fauna by the large size of the pronotum, 

 which extends back over the first abdominal segment, the rudimentary 

 tegmina in the male and the absence of these organs in the female. 



The only Ontario specimens I have seen are three males and two 

 females, which I captured at Arner, Essex Co., on Aug. 9, 1901. They 

 were found in the more open parts of a dry upland wood, consisting 

 chiefly of oak and other hardwoods. Most of them were found on the 

 short grass which was growing on the slopes of a ravine in the wood. 

 Sub-family STENOPELMATIJST^. 



The only genus represented in Ontario is Ceuthophiius, and it is a 

 very difficult one to deal with, only the .matured males of many species 

 being separable in anythuig like a satisfactory manner. 



Through the kindness of Mr. Henshaw I vvas able to compare my 

 specimens with those in the Scudder collection, and found that our 

 commonest species is undescribed, and that Scudder's types of terrestris 

 include two species, one of which is identical with C. iieglectus, Scudd. 



The characters which I find of most value in separating the species 

 of this genus are the form of the sub-genital plate and ninth dorsal segment 



