HAMILTON: HETKROCEPHALUS, AFRICAN lURROW I .\ (i RODENT. 183 
stygiiis. Thomas (1903) has made HclcroccpJialus phillipsi a new genus, 
Fornarina phillipsi, on the basis of its dentition, molar 3 being absent in 
this form. All the species, with the exception of Foniariiia, are based on 
minor differences in size, together with slight dift'erences in skull char- 
acter^ and the di>tribution of the various forms. 
Hollister (1917), in a study of 12 specimens from one general region, 
found the characters used to separate these forms from Heterocephalus 
glabcr were all accounted for by individual variation. He therefore 
groups all these previously described forms as synonyms of H. glabcr. 
The specimens I have studied agree essentially with Heterocephalus 
aiisorgci described by Thomas. Externall}' they can not be separated 
from the three alcoholic specimens I have examined in the U. S. National 
Museum. But a careful study of the skeleton reveals essential differences 
from the specimen of //. glabcr which was studied by the Italian anato- 
mist,--. F'arona and Cattaneo. Dift'erences in the number of ribs, processes 
cjuite dissimilar and minor variations can not l)e accounted for too readily 
by individual variation. I do not believe it advisable at this time to make 
a species or even a subspecies with the scant material at hand, but with 
more material other investigators may find some well-defined forms. 
I,iti-:r.\tl RI-: Cited. 
Allen, irldxcr M. 1912. Xew African Mammals. Bulletin Mus. Com]:arali\c Zool- 
ogy. \'()1. LI v., No. 14. 
Drake-Brockman, R. E. 1910. The Mammals of Somaliland. Hnrst and Blackett, 
Ltd. London. 
Hollister. X. 1919. East African Mammais in the U. S. National Museum. U. S. 
Nat. Afus. Bull. 99. Pt. 2. 
Lonnherg. Einar. 1912. Mammals Collected by the Swedish Zool. Expedition to 
British East Africa, 1911. Kungl. Svenska Wnenskajisakademiens Hand- 
lingar. Band 48. No. 5. 
Parona, C, and G. Cattaneo. 1893. Note Sull Heterocephalus. Annali Del Museo 
Civico Di Storia Naturale Di Genova. Serie 2. A'ol. 13. 
Riip]iell. Eduard. 1845. Saugethiere aus der Ordnung der Nager. Aluseum 
Senckenhcrgianum. Frank fort-am -Main. 
Thomas. Oldficld. 1885. Note on Heterocephalus glahcr. Proc. Zool. Soc. Lon- 
don. Pp. 611. 
1885. Notes on the Rodent Genus Heterocephalus. Proc. Zool. Soc. 
London. Pj). 845. 
1903. On .Sjiecimcns of Naked Rodents from E. Africa. Proc. Zool. 
Soc. London. A'ol. 2, No. 22. 
