108 



AVIFAUNA COLUMBIANA. 



Order STEGANOPODES : Whole-webbed Birds. 



Family PHALACROCORACID^E : Cormorants. 



231. (221.) Phalacrocorax dilophus (Sic.) Nutt. Double-crested Cormorant. 

 Once detected in the District, many years ago. [751] 



Fig. 98. — Head of Cormorant, nat. size. 



Order LONGIPENNES: Long-winged Birds. 



Suborder GAVIiE : Laridine Birds. 



Family LARID^F : Gulls, Terns, &c. 



232. (212.) Larus argentatus smithsonianus Cones. American Herring Gull; 



"Sea Gull." 



Occasionally seen sailing over the river during the winter, but not 

 numerous. [773J 



233. (213.) Larus delawarensis Ord. Ring-billed Gull. 



Seen over the river during the winter months, more frequently than 

 the preceding. [778] 



234. (214.) Chroicocephalus atricilla {Linn.) Lawr. Laugiiing Gull. 



A rare visitor, probably only a straggler, during the late summer and 

 early autumn months. [7SG] 



235. (215.) Chroicocephalus Philadelphia (Ord.) Lawr. Bonaparte's Hooded 



Gull. 



Much more frequently seen than the preceding during the migrations, 

 being comparatively common in August and September. [788] 



236. (21(3.) Sterna anglica it/ion f. (S. aranea of the original edition.) Marsh Tern. 

 Bare; only occasionally seen during the late summer and early fall 



months over the marshes bordering the rivers. [792] 



