PERCHERS PETREL 707 



genus, if Pygoscelis (JOHNNY) be not recognized, but they seem no 

 further to require remark. Eudyptes, containing the crested 

 Penguins (known to sailors as Rock-hoppers or MACCARONIS), would 

 appear to have five species, and Spheniscus (JACKASS) four, among 

 which 8. demersus, the well-known " Cape Penguin," and S. mendiculus, 

 which occurs in the Galapagos, and therefore has the most northerly 

 range of the whole group, alone need notice here. 1 



PERCHERS, the rendering by popular writers of the word 

 INSESSORES, now almost wholly abandoned by systematists. 



PEREGRINE (Lat. peregrinus, wandering) an adjective often 

 mistaken for a substantive, and used as an abbreviation of 

 Peregrine FALCON, an expression that originally meant one of 

 foreign origin, regardless of the species. 



PERISTEROMORPH^E, according to Prof. Huxley's taxonomy 

 (Proc. Zool. Soc. 1867, pp. 459, 460), the sixth group of SCHIZO- 

 GNATILE, consisting of the Columbx (DoVE, PIGEON), but not to be 

 confounded with his 



PERISTEROPODES, a section of ALECTOROMORPM established 

 the year after (op. cit. 1868, p. 296), composed of the CURASSOWS 

 and MEGAPODES, being so called from the Pigeon-like structure of 

 their feet, in which the hallux is long and on a level with the 

 other toes, instead of being short and raised as in the other section, 

 Alectoropodes, and it was a consideration of this difference that led 

 to his important conclusions in regard to the GEOGRAPHICAL 

 DISTRIBUTION of Mammals and Birds before mentioned (page 313). 



PERITONEUM, a thin layer of connective tissue lining the 

 whole of the body-cavity, and enveloping the viscera, as well as 

 attaching the intestinal folds to each other and to the vertebral 

 column as MESENTERY. 



PETREL, the name applied in a general way to a group of 

 Birds (of which more than 100 species are recognized) from the 

 habit which some of them possess of apparently walking on the 

 surface of the water as the apostle St. Peter (of whose name the 

 word is a diminutive form) is recorded (Matt. xiv. 29) to have 

 done. For a long while the Petrels were ranked as a Family, under 

 the name of Procellariidse? and thought to be either very nearly 

 allied to the Laridse (GULL), or intermediate between that Family 

 and the STEGANOPODES ; but this opinion has gradually given way, 



1 The generic and specific distribution of the Penguins is the subject of an 

 excellent essay by Prof. Alphonse Milne-Edwards in the Annales des Sciences 

 Naturelles for 1880 (vol. ix. art. 9, pp. 23-81), of which there is a German trans- 

 lation in the Mittheilungen of the Ornithological Union of Vienna for 1883 (pp. 

 179-186, 210-222, 238-241). 



2 Most commonly but erroneously spelt Procellaridas. 



