66 PROCEEDINGS OE THE ACADEMY OF 



fuscous occupies from to in the type of " yucatanensis" and 

 other skins of the same, shot at the same time by the same person ; 

 from f to i on different feathers of the tail of the Bahia specimen 

 " compared with type of 'erythrocercus' in Mus. P. L. S. ;" from i 

 to ^ in the Parana and Paraguay skins ; from ^ to ^ in some Central 

 American skins ; and then we have \-^ to nil in a Nicaraguan 

 (S. I., No. 41,189) and in various North American skins. Com- 

 ment is unnecessary. 



As the foregoing synonym}' may be regarded with mistrustful 

 surprise, it becomes me to state my case explicitly. " Tyrannus 

 irritabilis Vieill." is generally enumerated amongst the synonyms 

 of crinitus correctly so, leaving out of consideration the varieties 

 of the latter. But Vieillot's bird, being based on Azara, is of 

 course South American, and I have yet to see pure crinitus from 

 that portion of the continent, all my South American specimens 

 being characterizable as above. So we have "a local habitation 

 and a name," as firm ground for further investigation. 



I take the Nos. 16,349, 16,348 (Paraguay and Parana) as 

 being unquestionably the Azara- Vieillot bird ; they are both dis- 

 tinguishable from United States crinitus by the characters above 

 detailed ; but one of them has the fuscous stripe along the inner 

 web much broader than the other. 



Next, the Bahia skin (Mus. G. N. L.), as I see by the label, has 

 been compared with the type of erythrocercus, in Mus. P. L. S., 

 and found identical. It is in poor plumage, quite brownish above, 

 and " streak}'" below, and has the fuscous rather broader still, but 

 there is less difference in the breadth of the fuscous in this speci- 

 men, and in No. 16,348, than there is between 16,348 and 16,349. 

 All three are unquestionably identical. This fixes the status of 

 ""erythrocercus." 



Then, the type of "yucatanensis" Lawr. 1871 ( = "mexieanus'' 

 Lawr. 1869), now in my hands, has the rufous and fuscous exactly 

 as in typical " erythrocercus," and is in other respects a duplicate 

 of the latter. That Mr. Lawrence did not recognize this identity is 

 doubtless due to the fact that his example of "eiythrocercus" 

 was not in his hands at the time. When he published "yuca- 

 tanensis (based on the same Yucatan specimen he called " mexi- 

 canus" in 1869) lie did so simpl}' upon Dr. Sclater's announcement 

 that mexicanus Kaup was the bird called " cooperi" by Baird 

 quite a different variety, and usually held to be a different species. 



[July 2, 



