508 BIRDS OF rilE (iAI.ArAGOS ABCHIPELAGO-IUDGWAY. vol.xix. 



perhaps not excelled by that of auy othei' member of tlie family Fiin- 

 gillidii' ill its extreme thickness, in. others (meinbeis of the so called 

 genus Ca ft amis) slender and de(;urved, in others very acute, with 

 straight outlines, and in others still elevated and arched at the base. 

 The most extreme forms are, however, so gradiiall\ connected by inter 

 mediate types, that there -seems no possibdity of satisfactorily subdi 

 viding the genus into two or more sections. The extreme modifications 

 of the bill and some of the connecting forms are shown in the outline 

 illustrations on Plnte LVII, 



The reduction of Gavtorms to a synonym of (ieospiza has alieady 

 been made in my pai)er describing the new species of Galai)agos birds 

 in Dr. Baur's collection,' in which is announced ''the discovery of 

 species which absolutely bridge the previously existing gap between 

 the so-called genera (lenapiza and Cactornis, thus necessitating the 

 suppression of one of these names (the latter, according to the rule of 

 priority).'' 



Dr. r.anr, who has had the advantage of studying these birds in life, 

 disapproves of this, as the following extract from one of his letters 

 will show: 



I should like to make a few remarks, if yon will permit me, al.oiit Cad ornis and 

 Geos})iza. Yon ]ila(e the species of these two }:^enei\< in one jrenus, (ieospiza. I do 

 not think that this is natural. Both have their i)e(uliar representatives on the 

 different islands, and if you plate them to.aiether tiiis ]..MMii r .lifferentiation of 

 each is lost siijht of. (actnniifi is more slen<ler than (Ieospiza, and lias many more 

 black individuals. I would keep the two .^enera apart, and would not hesitate to 

 place C. propinquaiu ('(idorins. 



I am quite willing to adopt Dr. Barn's views concerning the position 

 of G. jrropinqua, which I had compared with (;. coniro.stris (a trnc 

 Geoapiza); but, while jplmitting that it would br very convenient to 

 recognize Cactornifi it any definite characters could be lound. I am still 

 of the opinion that not a single character can be found which will serve 

 to .separate them. The character which comes nearest to doing so is, 

 apparently, the relative width of the mandible l)etween the bases of 

 the rami to the length of the gonys, which is very much less in typical 

 ''Cactoriiis" than in ti ne Geospiza. This greater compression of the bill 

 even serves to trenchantly separate ^'Cdctornis'' propinqiia from G. 

 conirosfris, some individuals of wdiicli are almost precisely alike in the 

 lateral profile and measniements of the bill; but the use of this char 

 acter as a generic one would necessitate the removal of Geospiza (li(Ji- 

 cilis and G. acuiirostris, perhaps also G. parrula, to Cactoniis; and it 

 is difficult to see how the group can be divided into two genera without 

 one or two more being necessary: for there is certainly more difierence 

 between .such species as Geospiza maf/inrosfrls and G. pachyrhyncha on 

 the one hand and G.fuliginosa, G. debilirostris, etc., on the other, than 



'Descriptions of Twenty-two New Species of Birds from the Gahipaj^os Islands. 

 Proc. U. S. Nat. Mus., XVII (advance sheets published November 15^ IS!>4) i.d 

 357-370. " ■ 



