30 The Oologists' Record, June 1, 1923. 



*FaIco peregrinus brookei. Lesser Peregrine Falcon, c/4. Morocco- 

 Rare in collections. 



*FaIco pelegrinoides pelegrinoides. Barbary Falcon, c/4, c/2. 

 Morocco, c/3. Algeria. 



*Falco hiarmicus hiarmiciis. South African Lanner. c/4. Vaal 

 River, Potchefstroom, Transvaal, October 8th, 1906. I do 

 not know of another set. 



Falco biarmicus erlangeri. North African Lanner. I have also d. 

 set of 3 of these rare eggs from Algeria. 



Falco biarmicus f el deggi. European Lanner. c/4. Turkey. These 

 may or may not be correctly identified. Mr. Gordon does 

 not give his locality, but it is certain that S. Russian eggs are 

 always those of F. clierrtig cherrug. 



Falco rnsticolus islandus. Iceland Falcon. 2/4, c/3. Iceland. 

 The set of 3 are the largest and most beautifully marked eggs I 

 have ever seen. .One set of 4 is normal, but the other .set are 

 a second brood, and are very small dark eggs, not much larger 

 than Peregrine Falcons'. 



Icracidea herigora berigora. Striped Brown Hawk. I think Mr. 

 Gordon's eggs are more probably those of /. b. orienfalis, from 

 the locality, unless, indeed, they come from the interior. 



Pandion haliactus haliactns. Common Ospre3^ My series of this 

 is nearly as fine as that of the American form. I have two 

 pairs and a single from Scotland, all old eggs and five sets from 

 the Continent. 



THE CRITERION FOR THE TRINOMIAL. 



By E. C. Stuart Baker, F.Z.S., F.L.S. 



Field naturalists and scientific egg-collectors now so universally 

 accept the recognition of sub-species and the use of trinomialism, 

 that I hope no apology is needed for the appearance of this article 

 in a paper devoted primarily to egg-collecting pure and simple. 



In " The Auk " for July, 1921, an excellent article appeared by 

 Mr. J. Grinnell on this subject, in which he writes : " The criterion 

 " for the trinomial mvist not be closeness in general appearance, but 

 " it must be by inter gradation, either by way of geographic blending 

 " or by way of individual variation, determined strictly as such." 



