122 nuKEKDisaa of the xatjoxal mtsEvm. vouix. 



wivw iiitnciilatu alwsiys. v\v\\ in mjuTontorons tonns of <liiiiori>lii<' sju*- 

 <'i«»s, extending: somrwluit, jjrinMnlly coiisidcrjiblx , lu'yond tlu' middle 

 of tlu' toj^iniiia. Mind Irmora moderately lonj; and slender, tlie inte- 

 rior {genicular lobe with at least a darker basal sjjot oi" transverse 

 band, the hiinl tibial' with a variable iiiind>er of s|)ines (generally nine 

 to fonrtern) in the outer series, by rare exi-eption ('i;;ht oidy. Abdo- 

 men more or less compressed, the sides of the lirst sejinient with a <lis- 

 tinet tympanum, the extremity in the male more or less sometimes 

 stron;;ly elavate, usually ('<uisiderably recurved, the sub<,'cnital plate of 

 variable form, but always with the lateral marjjfins am|)liate at the 

 base and with no ilistinct apical tubercle, though not infre(|uently api- 

 eally produced <u- subtubcrculate and fre<|ncntly tumescent; centi 

 exei'cdiuji^ly variable in form, otti'u eidarjj:in«i" apically, always lamellate 

 e\cei)tiny: (the lakinus series — three species) where they are basally 

 globose, never styliform, rarely (the jmer series — two species) in the 

 least substyliform, jrenerally incurved and of about the len«^th of the 

 snpraanal ])late: furcula usually <leveloi)ed and to a very variable 

 extent, and with variable form: pallium rarely exserted; ovii)ositor of 

 female p'uerally fully exserted. 



The tyi)e of the ^enus is Acrid i urn femur-rubnim l)e (ieer. 



The nund)er of si)ecie8 of Melanoplus is so exceed in<iiy jjreat that I 

 have endeavored to display their relati(»nships in })art by sei)aratin<r 

 them into jxronps. Noticinj; how seldoni the characteristic j)arts of the 

 male abdomen ajireed in the short- win jjed and lon<?-win<ied forujs. not- 

 withstandinji" that one wojild look for their close atrreement, I have lirst 

 divitled them in the followinji' table into those which are fully e(|uipi)ed 

 M'ith ample or<»ans of tlij;ht and those in which these orjians are more 

 or less undevelopetl, and then have subdivided each according toother 

 characteristics, endeavoring thus to bring into close <'ontiguity those 

 which ai)peare<l to be most nearly allied. I was not a little surprise<l to 

 find in how few instances it was ])ossible to combine the brachypterous 

 and macroi)terons species in any one of these groups. Even in m<)st 

 of these, and especially in the dawsoni series (itself somewhat heter- 

 ogeneous on either side), the collocation is rather forced. The groups 

 into which I have divi<led the macropterous forms are far more iiat 

 iiral than those of the brachypterous species, and the portion of tli«' 

 table relating to the former is therefore much nu>re satislactory than 

 the other. 1 have more than once completely remodeled that relating 

 to the brachypterous species, but with no greater success than in that 

 HOW presented. 



Much to my surprise. I find but a coujde of species in this genus (.V. 

 ihnrscml, M. marf/inntus) in which there is complete dimorphism shown 

 in the full development on the one hand and extreme Jibbreviation on 

 the other of the organs of tlight. In other species, especially in M.fnsn- 

 aiuH and .1/. crtrcmus. there is considerable variability, but nowhere 

 else is it carried to this extreme. It is, however, found in Dendrotetti.i) 



