XII TABLE OF CONTENTS. 
Page. 
Key to the Species and Subspecies of Larus......-------+-rs-r7rtrrrt 7" . a 
5. Larus hyperboreus Gunnerus......--.----------e0r cer "i 
6. Larus leucopterus Faber.....-.-.----------2eer ere oud 
ae Be no hc aeeiad al eacerynee reyes 593 
7. Larus kumlieni Brewster ....--....---------22-0rcrrrrr rt 
8. Larus nelsoni Henshaw........-..--.--------2e cere 595 
9. Larus glaucescens Naumann.........---------+--- Nien tinieeighiatie He rite nee 
10. Larus thayeri Brooks. .......--..--------+-+-+++- betes eee e eer eecee 600 
11, Larus marinus Linneeus............-------e-2 eect 601 
12. Larus schistisagus Stejneger............------+----++- bamadeeemen'os oe 605 
18. Larus affinis Reinhardt. ..............-------- eee e cece 608 
14. Larus occidentalis Audubon..........-.-.------+ eee cere tee 610 
15. Larus argentatus argentatus Pontoppidan. ..-----------------+-++--+- 612 
16, Larus vege (Palmén).......-.-------2-022 cece e etree terrestres 618 
17. Larus californicus Lawrence...........--------+e eee cere crete 620 
18. Larus delawarensis Ord.....-..-.--------20 222 eee cee eee etter ee 623 
19. Larus canus Linneeus........---- 2-0 ee eee eee cee eens 627 
20. Larus brachyrhynchus Richardson.......---.----+-----+----++2+2--0-- 632 
Genus 4. Chroicocephalus Eyton. ........-.---.-----+--2- eee eect eee eee 635 
Key to the Species of Chroicocephalus ..........--------+--+++--+--2+e eee e eee 636 
21. Chroicocephalus atricilla(Linneeus)......-.----------+++e eee eee eee 636 
22. Chroicocephalus franklinii (Swainson and Richardson).......---.-.--- 641 
23. Chroicocephalus philadelphia (Ord.).....--..-.--------------+--- Lee. 645 
Genus 5. Hydrocoloeus Kaup......--.....---22---------0- eee eee apaanncane 649 
24. Hydrocolceus minutus (Pallas)............----.-- 220-222 - eee eee ee 649 
Genus: G6; ‘Blasipus Bruchs cn. iccsuisieemoivetseategle's'etelstasine Siem ieates + Gers eter 652 
Key to the Species of Blasipus <...:.s<ssesss0<ssceesveeeceeuesescessses verse 652 
25. Blasipus heermanni (Cassin). ........-.--.-.-.---0----22 2c eee eee eee 654 
26. Blasipus fuliginosus (Gould)... ........2-...0022ee eee eceee cece eens 656 
Genus 7. Creagrus Bonaparte...........---2-.20--00 202 - eee eee eee eee eee eee 658 
27. Creagrus furcatus (Néboux)....--------------ee eee eee eee eee eee 659 
Genuisti8:.. emia: Wea th’xs2caaiieawa.aaedudetcndmcemecnurind asonea sae neeene 662 
28. Xema sabini (J. Sabine)..........--....----------22-2 22 cece eee eee 663 
Genus 9. Rhodostethia Macgillivray..........00. 202202 e eee eee eee 668 
29. Rhodostethia rosea (Macgillivray).......-...-----202- eee eee eee eee 669 
Famity Stercorarups#, THe SkuaAs AND JAEGERS..........-.----------+-- 6738 
Key to the Genera of Stercorariide.........-.. 22. - 2-2 eee cece cence eee eee 674 
Genus 1. Megalestris Bonaparte... .... 22.2... 2 2 eee eee cee eee eee eee 674 
Key to the Species of Megalestris............-.-----0--- 20 e ee eee eee eee 675 
1. Megalestris skua (Briinnich)............ 2.222.222 e ee cece eee eee 677 
Genus 2. Coprotheres Reichenbach..............--.--- 22 2ce cee cece eee eeee 680 
2. Coprotheres pomarinus (Temminck)............... 0.00.02 e cece ee 681 
Genus 8. Stercorarius Brisson... ...- 2.22.0... eee eee cece cc eee eens 686 
Key to the Species of Stercorarius............... 220.200 cee cece cece cece ee 687 
3. Stercorarius parasiticus (Linneeus).............0 00. eee ccc eee ee eee 687 
4. Stercorarius longicaudus Vieillot.......... 2.0.00 eee cee ee 694 
Susorper Atc#. THE AUK TRIBE............2.0..0 2002 c cece cece ee eee 700 
Faminy ALcipm. THE AUKS...........0.0-0 000002020 ccc cece eee e cece eee 701 
Key to the Genera of Alcide........ 2.2.02 2. c eee c cece ee 702 
Genus1. Plautus Gunnerus................ 2.02.20. c eee cece cece ee 706 
1. Plautus alle (Linneus)..............00000000.0000.0-0.-. acelin 107 
Genus 2, Pinguinus Bonnaterre. ........ 2.0.2.2... eee eee. 710 
2. Pinguinus impennis (Linnus).... 2.2.2.2... 00022 cece cece 711 
Genus 3. Alca Linnmus............... 2.0.20 cece eee cece cece eee eee cee. 713 
