492 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



ally, the same, the measurements must necessaril}" be the only factor 

 in detenu inino- the number, limits, and relationships of the several 

 forms. Looking- at the matter from this standpoint, it seems to me 

 that any orouping- of the various forms into species and subspecies 

 must be pureh' arbitrary, and almost certain to differ with different 

 persons; and I am still of the opinion, expressed on page -iiyS of my 

 paper,^ that "were 'lumping'"^ once begun there could be no end to it. 

 unless purely arbitrary limits were given to the species recognized, 

 and if followed to a logical conclusion might easih^ end in the recog- 

 nition of a single variable species, equivalent in its limits to the genus.'' 

 This observation, according to my views, applies with exactly equal 

 force to any attempt to segregate the forms into specific groups. There- 

 fore, it seems to me that if there ever was a case which justified the 

 avoidance of trinomials the present genus is certainly of that kind.^ 



^ Birds of the Galapagos Ai-chipelago, Proe. UT. S. Xat. Mus., xix, 1897, pp. 459-070, 

 pis. 56, 57. 



^The term "lumping" was intended to apply to the reduction of any (lefinal)ie 

 forms to the rank of subspecies, although the inference is not clear in the original. 



'Also the genera Camarhynchns and Certhidea. 



In order to demonstrate the extreme difficulty of satisfactorily using trinomials in 

 the present genus, I give below the average measurements (of males only) of the 

 forms recognized conjointly l)y Messrs. Rothschild and Hartert and myself. It is 

 true that these measurements are not absolutely correct, relatively, for I have not 

 lieen able to measure the very large series contained in the Tring Museum, and have 

 in some cases been compelled to use measurements taken by Messrs. Rothschild and 

 Hartert, and it is a well-known fact that no two persons can get precisely the same 

 measurements for the same individual specimen. Furthermore, in the case of Messrs. 

 Rothschild's and Hartert' s measurements only the mean and not the average can in 

 some cases be given. 



Species. 



GE0SPIZ.3E. 



1. G. magnirostris: Measurements 



from Sharpe and Rothschild 

 and Hartert 



2. G.pachyrhyiicha: Measurements 



from Rothschild and Hartert.. 



3. G. strenua: 36specimens, but tail, 



tarsus, and middle toe of 18 

 only 



4. G. darwini: 4 specimens, meas- 



ured by Rothschild and Hart- 

 ert (average) 



5. <T. conirostris: 5 specimens, meas- 



ured by Robert Ridgway 



6. G.propinqua: Sspecimens, meas- 



urements of bill by Rothschild 

 and Hartert 



7. G. hauH: 1 specimen (R. R.) 



S. G. dubia: 10 specimens (R. R.) .. 

 9. G.albemarlei: 2 specimens (R.R.) 



Wing. 



92.20 

 88. 00 



83.31 



84. 00 

 80. 77 



77.47 

 81.28 

 72.64 

 72.14 



Tail. 



48.51 



48.26 

 50.80 

 43.94 

 44.45 



Cul- 

 men. 



26. 6 

 25.20 i 



Gonvs. 



Width 

 of man- 

 dible at 



base. 



Depth 

 of bill 

 at base, 



23. 62 

 22. 20 



18. 50 

 17. 02 



15.00 

 17.27 

 14. 22 

 13. 72 



Middle 

 ''■ toe. 



