435 
Linn. Soc. London, ser. 2, vol. 1, pp. 371—497, plates 58—64. In using 
this fine work it is necessary to remember that the appearance of the 
ossicles is very different in different positions; thus in our fig. 1 (Pro- 
echimys) the manubrium of the malleus appears to be a narrow rod, spa- 
tulate at the end, but in another view it is blade-like. It is for this 
reason that we have often given two views of the manubrium. We have 
used the term processus cephalicus (p.c. in figures) for the process which 
is directed downwards from the head of the malleus in Muridae, giving 
support to the lamina. The long process of the incus we call the sta- 
pedial process, to avoid possible confusion. Other abbreviations used 
in the figures are: p.g. = processus gracilis; stap.m. —stapedius muscle; 
t.tym. = tensor tympani; orb.ap. = orbicular apophysis; p.m. = pro- 
cessus muscularis (for tensor tympani); Jam. = lamina. 
Sciuridae. 
Paraxerus jacksont (fig. 3). 
British E. Africa (E. A. Mearns). gt. U.S. N. M. 162218. 
Upper part of malleus subquadrate, with no processus gracilis; 
manubrium flattened, spatulate at end; processus muscularis, to which 
tensor tympani is attached, small, on inner bor- 
der not very far from base. Stapedial process of 
incus not modified at end. Head of stapes broad 
and flat; crura slender; a bony intercrural canal. 
The malleus is formed much as in other Sciuridae, 
except that the angle representing the processus 
gracilis is much less developed than usual. The 
spatulate manubrium is like that of Æutannas. han 
The incus is of ordinary form, but the stapedial Male. British East 
process is peculiar for lacking any apical modi- ia Sd Di Sanna) 
fication. 
The stapes is much like that of Pteromys nitidus as figured by 
Doran, and indeed the whole conformation of the bones suggests af- 
finity with Pteromys. 
Doran does not figure the ossicles of any member of the Xerinae, 
but notes that those of Xerus setosus are very similar to those of Tamias 
striatus. 
Myoxidae. 
Graphiurus sp. (figs. 4, 4a). 
W. side of Mt. Kenia, British E. Africa (J. A. Loring). Oct. 4. 
O. U.S. N. M. 164266. 
Malleus nearly as in Myoxus glis, as figured by Doran; there is an 
imperfectly developed (apparently imperfectly ossified) lamina, bordered 
28* 
