1852.] 187 



result of an attempt to arrange them, and to reconcile their synoaymes, in a 

 eecond edition of my catalogue of Strigidice in our collection. 



Of the interesting little bird at preBent described, two specimens, male and 

 female, are in a collection made principally on the coasts of Angola and Ben- 

 guela, during a recent voyage of the U. S. brig Perry, and presented to the 

 Academy by A. A. Henderson, M. D., Surgeon U. S. NavY, who was attached 

 to that vessel as a medical officer. I have taken the liberty of dedicating it to 

 Dr. Henderson as a slight testimonial to his profound and varied scientific ac- 

 quirements, and as a memento of our long-continued and pleasant friendship. 



7. Larut ffeermanni, nobis. 



Form, Bill rather long and slender, wings very long, extending beyond the 

 tail, first primary slightly longest ; tail truncate or slightly emarginate. 



Dimensions. Total length of skin from tip of bill to end of tail about 17 J 

 inches, wing 13|, tail 5J, bill from the angle of the mouth to the tip 2 J inches. 



Colors. Bill red, both mandibles tipped with black ; feet and legs dark ; head 

 white, which color gradually fades into an ashy lead color, enveloping the entire 

 body above and below ; darker above and on the wings, and paler beneath. 

 Secondaries tipped with white, which forms an oblique bar of white on the wing. 



Superior coverts of the tail pale cinereous, nearly white. Quills and tail 

 brownish black, the latter tipped with white. Shafts of the two first primaries 

 white on the inferior surface of the wing. 



Young. Rather smaller, total length about 16 inches, wing 13, tail 5, bill 

 from the angle of the mouth 2 inches. Entire plumage brown, dark on the 

 head and paler on the under surface of the body, quills and tail feathers brownish 

 black, the latter narrowly edged at the tip with white. 



Eab. Coast of California at San Diego, discovered by A. L. Heermann, M.D. 



Obs. This beautiful gull appears to belong to a group of species comprising 

 Larus Belcheri, Vigors, L. erythrorynchus, Gould, and others, all of which in- 

 habit the shores of the Pacific ocean. It is most nearly related to L. Belcheri, 

 but is not so large, and has the head pure white, which is not the case in that 

 species. In the description of the latter (in Zool. Jour. iv. p. 328,) the rump 

 is described as white ; in the present bird the rump is dark ashy, but the su- 

 perior coverts of the tail nearly white, and in the young bird they are dark 

 brown. 



I have dedicated this handsome species to my friend Dr. Heermann, as a token 

 of acknowledgment due to his accomplishment as a naturalist, and his great 

 perseverance and success as a scientific traveller. 



8. Mergus americanus, nobis. Wilson's Am. Orn. viii. pi. 68. Aud. B. of Am. 

 pi. 331. 



Obs. I propose this name for the common bird which has hitherto been re- 

 garded as identical with the European species well known as Mergus mergan- 

 ser, Linn. It is, however, specifically quite distinct. In the American bird the 

 prolonged feathers of the head are almost restricted to the occiput and neck be- 

 hind, but in that of Europe they commence almost at the base of the bill, and 

 are erectile and crest-like. On the large wing coverts in the American species 

 there is always an exposed and conspicuous bar of black, which, in the Euro- 

 pean species, is entirely concealed by the lesser coverts. This character is suffi- 

 cient for the purpose of the practical recognition of the two species in all the 

 specimens that I have ever examined, and may be observed on comparing any 

 plates of the two species that I have seen, but especially Wilson Am. Orn. viii. 

 pi. 68; Aud. B. of Am. pi. 331 ; Selby, 111. pi. 57; Gould B. of Eur. v. pi. 39; 

 and Korner Skandinaviska Foglar pi. 57. 



9. Anser parvipes, nobis. 



Form. Generally resembling A. canadensis^ Linn., but not so large, and with 

 the bill and feet much smaller, the latter being not much more than half the 

 size of that species. Upper mandible not so strongly serrated on its edges, 

 tarsi slender, tail rather fully developed. Possibly a Bernicla. 



29 



