33- SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



Trouessart (Catalogus ]\Iammalium, i, fasc. iii, p. 663, 1897) uses it as a 

 subgenus for Lepus cuniculus Linn.eus, the only existing species. 



Major (Trans. Linn. Soc. London, 2d sen, vii, ZooL, November, 1899, p. 

 514) regards it as a genus containing two species " O. cuniculus (Linn.); 

 O. crassicaudatus (Geoffr.)." In the present paper the latter is regarded as 

 the type of the genus Pronolagus. 



Recently Thomas (Ann. Mag. Nat. Hist., ser. 7, xi. January, 1903, pp. 78, 

 79) following Major has used Oryctolagus in a generic sense. 



In the present paper it is regarded as a genus for the rabbits, heretofore 

 commonly known as Lcpiis cuniculus. 



PICA 



Proposed by Fischer (Das National Museum Naturgesch. zu Paris, 11, 126, 

 1803) as a correction of Pika Lacepede, fide Palmer (North American Fauna, 

 No. 23, January 23, 1904, p. 537). 



PIKA 



Used by Lacepede in 1799 (Tableau des Divisions de INIammiferes, 1799, p.- 

 9) for the Alpine pika, called Pika alpinus, the only mentioned species, and 

 accordingly the type. 



It is used in the present account as a subgeneric term to include Ochotona 

 (Pika) alpina and its related species, embracing all the North American 

 forms. 



ROMEROLAGUS 



Proposed by Merriam (Proc. Biol. Soc. Washington, x, December 29, 1896, 

 p. 173) as a genus for a remarkable rabbit found on the west slope of Mount 

 Popocatepetl, Mexico. The type and only species in the genus is Romerolagus 

 nelsoni Merriam. 



Herrera (Mem. Revista de la Soc. Cient. Antonio Alzate, xiv, 1899-1900, 

 p. 380; La Naturaleza, 2d sen, tomo iii, 1898, p. 80) considers Romerolagus 

 nelsoni to be a member of the genus Lagoniys, a view which is entirely 

 untenable (Nelson, Soc. Cientifica Antonio Alzate Mex., Revista Cientifica 

 y Bibliografica, num. 3, 1901, p. 33, figs. 1-6). 



Major (Trans. Linn. Soc. London, 2d ser. vii, Zool., November, 1899, p. 514) 

 regards Romerolagus as one of four subgenera of Sylvilagus, the other three 

 being Tapeti, Limnolagus and true Sylvilagus. 



Stone (Proc. Acad. Nat. Sci. Philadelphia, 1900, p. 462) regards it as one 

 of three genera forming the Leporidfe, the other two being Caprolagus and 

 Lepus. 



Romerolagus is here recognized as a well-marked genus of the family 

 Leporidae. 



SYLVILAGUS 



This was first proposed by Gray (Ann. Mag. Nat. Hist., 3d ser., xx, 1S67, 

 p. 221) as a generic term for "Lepus Section D" of Baird (Mammals of 

 North America, 1857, p. 578). The species first mentioned by Gray is Syl- 

 vilagus nanus (Schreber), a synonym of Sylvilagus sylvaticus (Bachman), 

 whose specific name was undoubtedly the origin of the word Sylvilagus. It is 

 evident that Gray had Baird's account in mind and merely copied the synonymy 

 of Sylvilagus sylvaticus as given by Baird, and in this way he happened to 

 use Schreber's name nanus. As the animal formerly known as Sylvi'agus 



