NORTHWESTERN MEXICO. 327 



Fam. Plotid^. 



299. Plotus anhinga Linn. 



" " Finsch, Abh. nat. Ver. zu Bremen, 1870, p. 362. 



Mazatlan, Bischoff; Eio Mazatlan, Grayson. 



« Common in the fresh water lagoons, Mazatlan River and Rio Santiago ; numerous in the small river of 

 Tepio, and Lake Chapula, near Guadalajara. In this re^on it is a constant resident, and buUds its nest in 

 trees, near, or over, fresh water-lagoons or streams." 



Fam. PsiETHOKNID^, 



300. Phceton cethereus Linn. 



Finsch, Abh. nat. Ver. zu Bremen, 1870, p. 362. 



Coast of Michoacan, Xantus 



•'Usually found far out at sea and in the Gulf of California. Breeds on the Island of Isabel, near San 

 Bias." 



Fam. Laeid^. 



301. Larus delawarensis Ord. 

 Mazatlan, Grayson. 



" Common in winter months only." 



302. Chroicocephalus atridlla Linn. 

 Mazatlan, Grayson. 



303. Chroicocephalus franMinii (Swains.). 

 Mazatlan, Grayson. 



" Specimens procured in December ; a few others were seen in that month, but it is not common in this 

 locality." 



304. Chroicocephalus Philadelphia (Ord.). 

 Mazatlan, Grayson. 



"A few individuals were seen, and specimens procured, in a fresh-water lagoon near the sea-shore, March 

 27th, 1868. I have not seen one since." 



305. Blasipus heermanni (Cass.). 

 Mazatlan, Isabella Island, Grayson. 



"Not common, specimens shot on the sea beach near Mazatlan, in February and March; a winter visitant." 



306. Sterna galericulata Licht. 



« « Finsch, Abh. nat. Ver. zu Bremen, 1870, p. 359. 



Mazatlan, Isabella Island, Grayson. 



" Common throughout the winter months, and until the latter part of March, when they congregate on the 

 beaches in large numbers, and in a short time disappear from this locality for their breeding grounds." 



HXUOing BOST. SOO. KAI, BIST. VOL. It. 89 



