X. Contributions to the knowledge of Pectinator, a genus of Rodent Mammalia from 
North-eastern Africa. By Professor W. Prrers, F.W.Z.S. 
Read November 1st, 1870. 
[Puates XLVIII. to L.] 
Introductory Remarks. 
PECTINATOR SPEKII was first described in 1855 by Mr. E. Blyth, and named in 
honour of the late Captain J. B. Speke, who discovered this very curious Rodent during 
his expedition into the Somali country, where “it inhabits the large cellular blocks 
of lava on the sea-face side of the northern Somali sea-coast range, lat. 9° N., and long. 
AT’ E.”?. 
Mr. Blyth directly recognized its close affinity to Dr. Gray’s Ctenodactylus massonit 
from Northern Africa, from which he distinguished it because it has four molars 
above and below instead of three, and “by having the tail and ear-conch well deve- 
loped, a smaller eye, and apparently a general adaptation for more diurnal and less 
fossorial habits.” He regarded the peculiar group of African Rodents, consisting of 
Ctenodactylus, Pectinator, and perhaps Petromys, “as a separate family, about equiva- 
lent to the Chinchillide, to which, upon the whole, the Pectinatoride would seem to 
be more nearly affine than to any other known form.” 
In 1861 Dr. v. Heuglin, who met with the same animal in the Adail and Somali 
country, in the Bay of Tedjtira, between 11° 40' and 11° 45’ N., gave a diagnosis, with 
a figure of the whole animal, and a sketch of the skull and teeth*, and communicated 
at the same time a description and some interesting additions to Captain Speke’s notes 
on its habits ”*. 
Mr. William Jesse, connected as zoologist with the Abyssinian Expedition in 1868, 
captured several specimens of the Pectinator, when proceeding up the passes from 
Zoulla to Senafé®. These have been very kindly forwarded to me for examination 
by my friend Mr. Sclater, who is always indefatigable in promoting zoological science 
in the most unselfish and liberal manner. 
A more complete knowledge of this Rodent has been a great desideratum; for, 
although its close affinity to Ctenodactylus could not be doubtful, the affinities and 
’ Journal of the Asiatic Society of Bengal, xxiv. p. 294. 
? Proc. Zool. Soc. Lond. 1859, p. 234. 
5 Nova Acta Acad. Cs. Leop. Carol. Nat. Curios. xxviii. 1861, p. 1, Taf. 2. figs. 1, 5, & 6. 
* Petermann’s Geograph. Mittheilungen, 1861, p. 18. > Cf. Proc. Zool. Soc. Lond. 1869, p. 113. 
VOL. Vil.—Part vy. January, 1871. Bi 
