NATURAL SCIENCES OF PHILADELPHIA. 171 



11. A. gavia Coues, ex Pr. gavia Forst. (following G. R. Gray's authority.) 

 Small ; with the colors generally those of Cookii, including under wing coverts. 

 " Expanse 2G; bill 1-50; tibiae 1-75; tail 2-50," [Forst.] 



12. A. desolata Bp. ex Pr. desolata Goo. Daption desolatum Steph. Small- 

 est. With the general colors of Cookii. Wing 7-80 ; tail 3 40, its graduation 

 75. Bill less than one inch. Tarsus or middle toe about 1-00. 



13. A. macroptera Coues, ex Pr. mocroptera Smith. Ossifraga macroptera 

 Reich. Pterodroma mac. Bp. Pr. brevirostris Less. nee. Lawr. ? Pr. lugubris 

 T sen. Large ; wings long ; face gray ; tarsi yellow. 



14. A. fuliginosa Coues, ex Pr.fuliginosa Kuhl, sp. 12, (not fulig. Kuhl, sp. 

 27; not of Gm. Lath.; not Puff, fulig. Strickl. not Neclris fulig. Forst.) Pr. 

 atlantica Gld . Pterodroma all. Bp. Large. Everywhere fuliginous; feet dark 

 colored. Bill 1-35. Tarsus 1-60; middle toe and claw 2-20; wing 10-75 to 

 11-50 ; tail 4-50 to 5-00. 



15. A. aterrima Coues, ex Proc. alerrima Verr. Pterodroma aterr. Bp. Small. 

 Tarsi light colored, passing into black upon the terminal portion of the toes. 

 Wing 8-50 ; tail 3-50 ; bill slightly more than an inch. Tarsus 1-33. 



1G. A. Bulweri Coues, ex Pr. Buhveri Jard. and Selby. Thalassid. Bulweri 

 Gray. Pr. anjinho Heineken. Puf/inus cohimbinus Webb and Berth. Bulweria 

 columbina Bp. Smallfst. Proportionate length of tail to wing as 4-50 to 8 ; 

 graduation of tail 1-75 to 2-00. Bill -85 ; tarsus a little longer. 



17. A. Macgillivrayi Coues, ex Thalassidroma (Buliveria) macgillivrayi G. R. 

 Gray. Like Bulweri; bill larger; no sooty brown on wings. 



18. A. cap.rib.'ei Coues, ex Pterodroma carribsei Carte. " Blue Mountain 

 Duck," Gosse. 



Genus II. Pagodroma Bp. 1855. Bill very short, moderately strong and 

 compressed. Forehead flattened ; and lengthened by the extension forward of 

 the feathers. Interramal space narrow, densely feathered. Nasal tubes short. 

 Hallux unusually developed. Tail long, broad, but slightly rounded. 



19. P. nivea Bp. ex Pr. nivea Gm. Daption n. Steph. Thalassoica n. Reich. 

 Proc. Candida Peale. Pagodroma var. major Bp. Entirely white. Subject to 

 great variations in size ; forming var. minor Bp. 



Genus III. Daption Steph. 1825. Bill much dilated, unguis small and weak. 

 Interramal space wide and partially naked, oblique sulci on inner face of cut- 

 ting edge of mandible. Fasal tubes long. Hallux of ordinary size. Tail 

 rather short, moderately rounded. 



20. D. capensis Steph. ex Pr. capensis Linn. Pr. nsevia Briss. Pr. punctata 

 Ellin. Spotted with black and white on upper parts. 



Section PRIONEJE (Bp. 1855.) 



The upper mandible is furnished near its edge with laminated serrations. 



Genus I. Halob.exa Is. Geoff. External form of bill much that of JEslrelata ; 

 serrations few and inconspicuous. Tail truncated. 



1. H. coerulea Bp. ex Pr. cocrulea Gm. Pachjptila coerulea 111. Steph. Pr. 

 similis Forst. Pr. Forsteri Smith, nee. Lath. Tail tipped with white. 



Genus II. Pseudoprion Coues. Serrations poorly developed or quite obso- 

 lete towards end of bill. Lateral lamellae of bill normal, their free edges un- 

 inflated. Culmen concave ; lateral outline of bill straight. Interramal space 

 narrow, well feathered. No sulcus for reception of fringe. Tail moderately 

 long and rounded, contained nearly twice in the wing. 



1866.] 



