HYSTRIX 549 



molars but showing more tendency to irregularities. Lower 

 teeth with the same pattern reversed, the outer side with one 

 simple, oblique, backward sloping fold, the inner side with three 

 folds, the posterior and middle of which are usually simple, the 

 anterior complex and tending eventually to become divided into 

 two or three irregularly shaped islands arranged somewhat in a 

 spiral. The premolar shows the same tendency as the corres- 

 ponding upper tooth to become, irregular in details of enamel 

 pattern, though the fundamental plan of its folds appears to be 

 always the same as in the molars. 



Measurements. — Young adult (probably female) from Vizziri. 

 Sicily (approximate) : head and body, 600 ; tail, 40 ; hind footj 

 75. Immature individual from Province of Rome, Italy (approxi- 

 mate) : head and body, 600 ; tail, 50 ; hind foot, 85. For cranial 

 measurements see Table opposite. 



Specimens examined. — Seven, from the following localities : — 

 Italy: Near Rome, 4 (B.M. and U.S.N.M.) ; Vizzini, Sicily, 2; no 

 exact locality, 1 (Stockholm). 



3. Rome, Italy. Genoa Museum (b). 97. 2. 22. 1-3. 



2,juv. Vizzini, Sicily. J. I. S. Whitaker (p). 3.4.21.1-2. 



Family MUSCARDINLD^E. 



1821. Myoxidse (misprinted Myosidse) Gray, London Med. Repos., xv, 



p. 303. April 1, 1821. 

 1857. Myoxina Blasius, Saugethiere Deutschlands, p. 285. 



1898. Qliridx Lydekker, Zool. Rec. xxxiv. (1897), Mamm. p. 27, 1898. 

 Not of Ogilby, 1837. 



1899. Muscardinidm Palmer, Science, N.S., x, p. 413, September 22, 1899. 



Geographical distribution. — Warmer portions of the Old World 

 from Japan to England and from central Sweden south through 

 Africa. Absent from Madagascar, the Malay Archipelego and 

 Australia. 



Characters. — In general as in the Muridse (p. 591) but 

 caecum absent, jugal bone larger and forming a more important 

 mechanical part of zygoma (in some genera approaching the 

 condition characteriatic of the Sciuridse), angular process of 

 mandible bent outward at middle so that its lower border 

 bears a noticeable secondary angle, and cheek-teeth always 

 rooted, brachyodont, their crowns with transverse cross ridges 

 variously arranged and sometimes obsolete, but referable to a 

 primitive 3-ridged pattern ; one premolar typically present in 

 each jaw. 



MemarJcs. — Six genera of Muscardinidse are currently recog- 

 nized, four of which occur in Europe. They are mostly arboreal 

 animals with habits and aspect somewhat intermediate between 

 mice and squirrels, but readily distinguishable from the Muridse 



