SOll I'll \M I uu v\ I'UM IK V 



admitting the strength of the statement thai the descriptions 

 Walker are not ver^ much worse than those of some other wrii 

 it is the opinion of the writer that, as Osten Saeken has demonstra 

 ted, the^ mean nothing. \'<t\ ofteti several genera or eveu families 

 are represented in the types of a mm ^ Other writers h 



made their mistakes, and poor ami incomplete deseripthms are in 

 abundance, bul no others have habitually been guilh of furnishing 

 a description of portions of the anatonn of several species, under h 

 name thai din rts must now Attempt to ii\ upon one spc< 



mi addition to the ottfenseof faulty characterisation T>> place the 

 uiiivr.'-nri.! descriptions of this writer ai the end of the various 

 families seems to afford him as much i ; - he dcsei 



li was formerly the practice of entomologists not t«> hesitate be 

 euuse the> >I'>1 not know from what quarter of the earth a specimen 

 before them might have come, bul t>' describe it forthwith Fhe 

 number of such descriptions burdeuing the literature of Oipterol 

 i- considerable! and mam doubtless appl} to South Vmcrioan spe 

 t>ies in this catalogue, H>r the convenience of the student "t' the 

 South Vmericaw forms, as well as of exotic Diptera in general, 

 pains have been taken i«' bring all th thcr l x hej are placed 



;u ilu- end »'i the families 



\ di times tin' write* has been under th on i>- 



I >i \Y illiston tf it were not lor the generous lo : all 



books in his library, including main ottscure papers that it \\*>uLI 

 have Ikhui impossible to >>l<iain through tin- regular channels, this 

 work could not ^ch have been contemplated Mr Hugo Kahl, 

 of the University ol Kansas, has ks kindl) furnished most valvw 

 I m,v 1 1 v ■ h i ■ called attention to some Almost inaccessible de 

 lotions that \\>miM probahh otherwise hav« been missed, has 

 ottered critical suggestions on certain points, and has loaned books 

 i'umu lii- own private libt *ry. M e thanks due to IM I 



() Howard tin sending books lYom the library ol the l S l*eu 



mrin ol Vgl ICUltUrf 



l'|, v . vx mi, -I wi ihe I tO d '' 'Mi in-liMi -. i l'r 



I'lu-. catalogue is preliminary, and like th the 



North Vmerlenn it uo sense critical f ftbrt 



i., V n to include all ol the existing descriptions, and the writei 

 youe ^l |1 ' untie ions oi has other criticisms i>> I" 



dirm to In • attention 



