BIRDS OF SOUTHERN VERACRUZ — WETMORE 299 



what elongate and was about the size of the terminal joint of my little 

 finger. On dissection, I found that the pouch was connected with the 

 interclavicular air-sac, and by that means with the lungs. The snap- 

 ping sound described apparently came through its sudden distension 

 with air. The structure was new to me and has been noted by few 

 naturalists. 



On inquiry I learned that Dr. George M. Sutton also had observed 

 this curious structure during his work in eastern Mexico, and his notes 

 on it, which he showed me at the time, he recently has elaborated with 

 preserved material in collaboration with Perry W. Gilbert. 53 The 

 earliest published note on the sac that I have found is by Cabot, 54 

 who saw it in the subspecies found in Yucatan, Psilorhinus mexicanus 

 vociferus, though he was wrong in his description of its anatomy. He 

 writes "they have a most peculiar formation in the trachea, being a 

 membranous bag, coming off between the rings, and half way down, 

 and intimately connected with the skin of the neck." It was first 

 described accurately by Crandall, 55 who recorded the sac in P. m. cyan- 

 ogenys in Costa Rica and also observed it in a captive specimen of 

 P. morio in the collections of the New York Zoological Society. This 

 bird produced the popping sound regularly. On dissection of this 

 bird after its death Crandall recorded that the sac was a diverticulum 

 from the interclavicular air-sac. 



Family TROGLODYTIDAE 



HELEODYTES ZONATUS RESTRICTUS Nelson 



Heleodytes zonatus restrictus Nelson, Auk, 1901, p. 49 (Fiontera, Tabasco). 



The series obtained is as follows: Tres Zapotes, March 7 and 15, 

 1939, February 27, March 3 and 27, and April 5, 1940; Tapacoyan, 

 May 11 ; below 1,000 feet elevation on Cerro de Tuxtla, May 7. They 

 were fairly common, usually in little groups, but except when calling 

 they were often unnoted, as they kept in heavy cover of dense leaves 

 and tangles of vines. They ranged from the tops of bushes into the 

 taller trees. Rarely they were observed passing with tilting flight 

 between tracts of brush. The croaking, creaking calls are strange and 

 curious, and they are known locally as carrasquita from their notes. 



The series obtained appears to be intermediate between true 

 restrictus of Tabasco and the style of this wren found from Veracruz 

 City northward and westward. It differs from restrictus in the 

 smaller amount of spotting and barring on flanks and abdomen but is 

 definitely more heavily marked than birds from farther north. The 

 species is one that is in need of revision, particularly since no type 



5S Condor, 1942, pp. 160-165, figs. 58-60. 



44 Cabot, S., Journ. Boston Soc. Nat. Hist., vol. 4, 1844, p. 465. 



88 Zoologica, vol. 1, No. 18, Sept. 1914, p. 337. 



