258 



much darker in the American bird than in the European, and 

 the white line which runs along the inner edges and forms 

 their tips in the European bird, disappears in the American be- 

 fore it gets within half an inch of the tip ; besides being much 

 narrower. There are also some important differences in form. 

 The projecting point at the symphysis on the under side of the 

 lower mandible is more marked in the American than in the 

 European bird. The claws of the European bird are larger and 

 much more arched than those of the American. The bill of the 

 European bird is much narrower in proportion than the Ameri- 

 can, and is more bent. 



The specimen of S. acujlavida in his collection was procured 

 at Tancah,* on the coast of Yucatan, on the 25th of April, 1842, 

 and is mentioned in the appendix of Mr. Stephens's Incidents of 

 Travel in Yucatan, under the name of S. Boysii. 



Dr. Cabot also described the following species of Wren, 

 under the name of Troglodytes albinucha. 



Total length 



Length of wing from flexure 

 " tail 



*' head and bill . 



" bill along the ridge 



" bill along the gape 



Width of bill at feathers 



Depth " " . . 



Length of tarsus 



" middle toe with the claw 



" inner toe " " 



'* outer toe " " 



" thumb '' " 



Millimeires. 



. 140 



58 

 . 51 



38 

 . 17 



22 

 . 3-i 

 3f 

 . 20 



22 

 . 15 



16 

 . 17 



The bill is bent from the base to the tip. The claws are much 

 curved and very sharp. The head, back, and upper sides of the 

 wings and tail, brown ; a line of white, with black or dark brown 

 intermixed, passes over the eye, and meets with a similar line, 



* This is the name of a rancho situated on the site and amid the ruins of an 

 aboriginal city, and owned by the sons of a piratical captain, by the name of 

 Molas. It is nearly opposite the Southern extremity of the Island of Corumel, 

 lat. 20° 15' N. 



