^°^ i^(^'^n DwiGHT, Moults and Plumages, of Gulls and Terns. AQ 



Heleodytes zonatus restrictus, new subspecies. Tabasco 



Wren. 



No. 166,601, $ ad., U. S. National Museum, Biological Survey Collec- 

 tion. From Frontera, Tabasco, Mexico, collected April 26, 1900, by E.W» 

 Nelson and E. A. Goldman. 



Distribution. — Wooded coast plains of Tabasco. 



Subspecific characters. — Differs from t^'pical H. zonatus (from moun- 

 tain slopes of Vera Cruz) mainly in much heavier and transversely 

 broader black spotting on under side of neck and breast; rest of lower 

 parts much more dingy buff, heavily barred and spotted on sides and 

 flanks with black ; back more like that of zonatus but with little or no 

 traces of rusty buff suffusion. 



Dimensions of type. — Wing, 92 ; tail, 95 ; culmen, 24 ; tarsus, 29. 



Notes. — The very heavy black spotting and barring on the 

 underparts with the dull dingy shade of buff on the crissum 

 renders this form very readily distinguishable from typical H. 

 zojiatus. Its range appears to be restricted to the wooded coast 

 lowlands while we found H. zofiaitis only on the wooded slopes of 

 the Cordillera in Vera Cruz and Tabasco. We obtained ten 

 specimens of this new form at Frontera. 



THE SEQUENCE OF MOULTS AND PLUMAGES OF 

 THE LARID^ (GULLS AND TERNS). 



BY JONATHAN DWIGHT, JR., M. D. 



The importance of the moulting of birds from the standpoint of 

 the systematist becomes apparent if we stop to consider that each 

 moult marks a point of transition from one plumage to another 

 and is therefore a key to their relationship. It is, however, not 

 far from the truth to say that the natural sequence of pkmiages 

 and moults is but imperfectly understood in many species, while 

 the times of year at which moults occur and the areas of feathers 

 involved in partial moults, especially of young birds, are matters 

 still offerino; a wide field for investigation. 



