NO. 1530. THE DECTICIN.E OF NORTH AMERICA— CA UDELL. 321 



This genus bears a striking- superficial resemblance to the European 

 genus Thyreonotus^ but is not sjstematicall}" related to it, having four 

 instead of two apical spurs beneath the posterior tibia. That the 

 genus Engoniasjns of Brunner is a synonym of Atlantwus is very 

 certain, it figure of the type of the former genus, a female, having 

 been sent to me by Brunner. This figure (fig. 29) shows very clearly 

 that it is an Atlmiticiis and quite certainly Jl. pachynierus. 



Enyoniasph Brunner would invalidate the later described AtJanti- 

 cus of Scudder had it l)een based on a named species, but it remained 

 invalid until the establishing of Atlantlcus m 1804. 



The species of Athoiticnx occur east of the great plains from 

 Canada to the southern States in the South, proba))ly extending west- 

 ward to California. So far as known they inhabit open woodlands 

 or dry hillsides, sometimes however being found in marshy meadows. 

 They are sometimes called "" shield-l)ack grasshoppers" and occur 

 from early spring, when the young nymphs issue and hop about in 

 the woods and along hillsides, till late in September in the Middle 

 States, when the last of the slowly moving adults are seen. Blatchley 

 sa^^s that in Indiana the}^ reach maturity in June. 



In confinement these insects will eat animal as well as vegetable 

 food, and \\\ nature probabh^ do not confine themselves to a vegetable 

 diet. The 3'Oung are active all day, and many fall a prey to insectiv- 

 erous birds and reptiles. The adults also hop about during the day, 

 and the males sti-idulate by day as well as by night. 



There are three described species of this genus. These are separable 

 as follows: 



KEY TO TlIK SI'ECIES OK ATLANTUTS. 



A. Lateral carina' of the i)ronotum .sharj). Cerci of the male ■with a short stout 



tooth situated about or beyond the middle on the inner side. 



B. Posterior femora long, more than two times as long as the pronotum. Ehtia 



in the male projecting beyond the pronotum a distance less than the width 



of the pronotal disk at the anterior margin. C'erci of the male with that 



portion beyond tiie inner tooth three times as long as tlic l)asal width 



dorsalis, p. 321. 



W. Posterior femora shorter, less than or scarcly two times as long as the pronotum. 



Elytra of tlie male projecting beyond tlie pronotum a distance equal to or 



greater than the width of the pronotal disk at the anterior margin. Cerci 



of the male with that portion beyond the inner tooth al)out two times as 



long as wide parlajmerus, p. 323. 



A''. Lateral canme of the pronotum distinct but not sharp. Cerci of the male with 



a long slender tooth situated much before the middle on the inner side 



yihbosuft, p. 32(). 

 ATLANTICUS DORSALIS Burmeister. 



Z)('d/c?(.s (/o)w/^/s BuKMEisTEK, Haudb. Ent., II, 1S3S, p. 713. 



Locvsia {Epliipjyigcra) dorsalis De IIaan, Bijdr. Kenn. Orth., 1S42, ]\ 17S. 



Thyrennoius dorsalis Scudder, Bost. Journ. Nat. Hist., yil, 1862, p. -154. — Hitch- 

 cock, Kept. Geol. N. IL, I, 1874, p. 370; Proc. Bost. Soc. Nat. Hist, XIX, 

 Proc. N. M. vol. xxxn— 07 21 



