ARDEID^E — THE HERONS — ARDETTA. 



71 



European species. This is a mistake. The cry of our bird is one quite as remarkable, 

 though said by some writers — but not by Richardson — to be (|uite different. Dur- 

 ing my residence in Cambridge, in the spring and early summer, its singular, resonant 

 cries could be heard at quite a distance, issuing from the Fresh Pond meadows early 

 in the evening, and even on cloudy days. They seemed to be uttered in a deep cliok- 

 iug tone, and have been well compared to the syllables ponqi-au-gdr. Dr. Bachman 

 describes it as a hoarse croaking note, sounding as if the bird's throat were filled with 

 water. By many these sounds are thought closely to resemble the noise made by 

 driving a stake in boggy soil; and hence the Bittern is popularly known as the 

 " Stake-driver," and also as the " Post-driver." 



It is an occasional visitant to Great Britain, where some five or six instances of its 

 capture have been recorded. 



According to the observations of Captain Bendire, the number of eggs in its nest 

 varies from five to seven. I have never met Avith more than four. Eggs in my col- 

 lection (No. 783), procured by Mr. Kumlien in Wisconsin, are of a rounded oval 

 shape equally obtuse at either end, and of a uniform brownish-drab color, neither 

 spotted nor having any tinge of green or olive in their shadings, as stated by some 

 writers. They range from 1.90 to 1.95 inches in length, and from 1.45 to 1.50 in 

 breadth. These eggs vary but little in size, shape, or color, and are hardly " pointed 

 at one end," as described by Yarrell. 



Gei^us ARDETTA, Gray. 



Ardcola, Bonap. Synopsis, 1828 (teste Gray, Gen. & Subg. 1855, 113). Type, Ardca exUis, 



Gmel. (Notof Boie, 1822 !) 

 Ardetta, Gray, List of Genera, App. 1842, 13. Type, Ardca minuta, Linn. 

 Erodiscus, Glogeu, Handb. L 1842, 410 (same type). 

 "ArdciraUa" (1855), Verreaux (teste Hartl. Orn. AV^estafr. p. 224). Type, Ardea Sturmi, Wagl. 



Gen. Char. Extremely small (the smallest of) Herons, or miniature Bitterns ; differing from 

 the true Bitterns chiefly in their diminutive size, and in the fact that the sexes differ in color.^ 



A. exilis. 



1 We can find no other difference in form or proportions between Botaiirus and Ardetta. In the sexed 

 specimens of A. involucris which we have been able to examine there is no sexual difference of plumage. 

 The sex of the single supposed female, however, may have been incorrectly determined. 



