NO. 1124. h'Fvrsrny OF Tur }fnr.AXopTJ—fiC''nr>ER. 123 



I'horfaliotcM, ;ui<l (htlalconofus, v.wh of wliicli is repioMMitiMl hy ;i sin^^^Ie 

 s]»e('ies. I have treated this mutter more fully in the Introduetion. 



Tiie present jjenns, so richly endowed with species, is naturally very 

 widely distribntetl, though so far as known it is completely contiiied to 

 the continent of Nortli America, an<l even does not <H'cnr, so far as 

 reported,' soiitli of Mexico. Within this rejjion it is as widespread as 

 all the other jjenera <'(Mnbined. It extends from the arctic circle in 

 Alaska and on the Mackenzie itiver. and trom northern liabrudor and 

 perhaps southern (Ireenland on tlu' nortli, to the extremity of Floiida 

 and southern Mexi<*o on the south, and fiom the Atlantic to the Pacitlc. 

 It is, however, far richer in species in the west than in the east. Only 

 seventeen of the one liun<lred and thirty-one si)ecies are foinnl exclusively 

 east of the Mississijipi IJiver, thonjrh four other eastern species barely 

 cross it; while in the Hocky ^Mountain re«;ion an<l west of it, and tliere 

 only, t'orty-nine- s])ecies are known, while thirty two others are found 

 only west of the Mississii)pi IJiver and seven western sjtecies barely 

 cross it to the east; six si)ecies, as stated in our introduction, ran<;e 

 from Atlanti(r to Pacitic; one occurs only north of our national bound 

 aries in Labrador, while nineteen others inhabit Canada: twelve are 

 fouuil only in Mexico, with ten others which it possesses in comnuui 

 with the Knited States. 



These lijjures show the western preponderance of the species better 

 than any summary of thetwenty-eijiht «itoui)s into which I have divided 

 the jjjenus, which, besides beinj» rather uneipial in the number of <'on- 

 tained si)ecies, often show an extremely wide distiibuti<Mi or more than 

 one center of distribution, in the latter case indicating?, ]»erhai>s, the 

 iini)erfection of the ^roupin^. Still, leavinjjf out the live jj^roups, each 

 of which contains one or more transc(UJtinental si)ecie8, it will be noted 

 that there are three others which compass the (continent — the uiaiu'us 

 (five species), plebejus (five species), and robustus (live species) series. 

 i)t' the twenty remaining, one-half, viz, the tlabellifer (six species), bow- 

 ditchi (six species), glaucipes (two species), utahensis (three species), 

 devastator (eight species), aridus (three species), rusticus (seven sjte- 

 cies), borckii (six species), cinereus (six species), and packarflii (live 

 species) series — extend westward to the Pacitic; while only live — the 

 inipudicus (one species), dawsoni (seven s])ecies). i>iu»r (two s]>ecies), 

 inornatus (three species), and jmiu'tulatus (two sj)ecies) series — reach 

 eastwar<l to the Atlantic coast; and the lemainiuff live — the lakinus 

 (three species), indijrens (one species), alleui (two species , au«i:ustipen- 

 iiis (four species), and texanus (five sjjecies) series — are found exclu- 

 sively, or abnost exclusively, west of the Mississip])i Kiv^er. 



One-half of the series are represented in Mexico, showing rather 



'One species, }[. hnrenl'ta, is r«'|)orte«l, \n lift., hy Brnniier to occur at Vnhlivia, 

 <'!iil«'; as its only other known localities arc ni the arcti*' rej;ions. 1 am inclined 

 t" tloubt the correctness of the determmatiou, and presunu' the material to be 

 insufficient. 



