124 PROCEEDINGS OF THE ACADEMY OF 



Family LAR1DM. 



Subfamily LESTRIDINJ3. 

 Of this, the first subfamily of the Laridce, there are at present known to 

 exist eight species, belonging to two genera. Of these, five v inhabit the 

 northern, and three the southern hemisphere. The five northern species are 

 all represented in North America. The following analytical table Will represent 

 the characters of the species and genera sufficiently well for our present 

 purposes. The diagnoses are purposely made as brief as possible, only the 

 most prominent features being noticed. 



Analytical Table of the Genera and Species of the Lestridince. 



I. Statura maximi, et forma robustissimi. Pedes et rostrum 

 validi. Tarsus brevior quam digitus medius cum ungue. 

 Rectrices mediae lata? vix ultra caeteras porrectae Genus Bpphagps. 



a. Rostri longitudo poll. 2, et ultra ; altitudo *75. Ad 

 anguli oris 3-00 poll. Ex maria arctica B. skua. 



b. Rostrum brevius, crassius. Ex maria antarctica B. antarcticus. 



II. Statura minores, et forma, graciliores. Pedes et rostrum 

 graciles. Tarsus non brevior quam digitus medius cum 

 ungue. Cauda iongior, et rectrices mediae valde ultra caeteras 



porrectae .' Genus Stekcoeaeius. 



1. Tarsi postice asperrimi. Rectrices mediae latae in 

 apices ipsas. 



a. Rectrices mediae caeteris 4 pollices longiores S. pomarinus. 



2. Tarsi postice subasperi. Rectrices mediae longae, rigi- 

 dae, acuminatae. 



a. Rectrices mediae caeteris 4 poll, longiores S. parasiticus. 



b. Similis S. parasitico ; sed major, Cauda tota longiore, 



plus rotundata S.Richardsoni. 



c. Similis S. pirasitico ; sed minor, rostro magis com- 

 presso, rectricibus mediis elongatis, apidb.is rotun- 



datis (Bp.) S. Hardi/i. 



d. Similis 5. parasitico. Sed etiam minor S. Buffono ; 

 rectricibus mediis lineari-acutis, rachide denudata 



rigida, pollice et ultra caeteras superantibus (Bp.) &. spinicauda. 



3. Tarsi postice subasperis. Rectrices mediae longissimae, 

 flexibiles, filiformes. 



a. Rectrices mediae caeteris 8 ad 10 pollices longiores.... 5. Buffoni. 



Genus BUPHAGUS Moehring. 



Buphagus, Moehring, Genera Avium, 1752, page 66, No. 71. Typus Larus 

 catarractes, Linn. 



Stercorarius, "Brisson," Vieillot, Nouv. Diet. d'Hist. Nat., 1817, 153. Typus 

 idem. (Sed non verus Stercorarius, Briss. cujus typus Larus parasi- 

 ticus, L. est.) Gray, Genera of Birds, 1849, 651. Degland, Ornith. 

 Europ. 1849, ii. 287. Bonaparte, Conspectus Avium, 1856, 206. Law- 

 rence, Gen. Rep. Birds N. A. 1858, 838 ; et aliorum auctorum. 



Catharacta, Briinnich, Orn. Bor. 1764, 32. Typus Cath. skua Briinn. Bona- 

 parte, Comparative List, 1838. 



Larus, (partim) Linnaeus, Systema Naturae, 1766. Gmelin, Systema, Natu- 

 rae, 1788. Latham, Index Ornithologicus, 1790. Meyer et Wolf, Tassch- 

 enbuch deutsch. 1810. 



Catarractes, Pallas, Zoog. Rosso-As. 1811, ii. 308. Typus C. skua. Steph- 

 ens, Shaw's Gen. Zool. xiii. 1825, 214. 



Lestris, "Illiger," Temminck, Man. Orn. 1S20 40. Typus L. catarractes. 

 (Sed non verus Lestris 111. cujus typus L. parasitica L. est.) Faber, 



[May, 



