644 MR. ST. GEORGE MIVART ON THE CRANIA_ [Nov. 22, 
Cat. des Prim. p. 78; Dahlb. Studia Zool. p. 210; Buffon, xiii. 
p- 210, pl. 30 (1765). 
Prosimia, Cuv. et Geoff. Mém. sur la Cl. des Mamm. (1795). 
Stenops, Kuhl, Beitr. p. 47, t. 6. f. 2-6 ; Wagner, Schreber, Suppl. 
i, p. 287, v. 151; Van der Hoeven, Tijds. p. 39. 
Nycticebus, Fischer, Syn. p. 70. 
Bradylemur, De Blainv. Osteogr. Lemur, pp. 12, 16. 
Arachnocebus, Lesson, Species (1840) p. 243. 
Characters.—Body and limbs slender; index finger short ; tail 
absent ; upper incisors very small and equal; first upper premolar 
elongated ; last upper molar quadricuspid ; last lower molar quinque- 
cuspid ; palate prolonged a little beyond the last molar; pre- 
maxillee projecting greatly forwards ; orbits closely approximated ; 
dorsal vertebree fourteen or fifteen ; lumbar vertebree nine. 
Hab. Ceylon: Pondicherry. 
Genus 3, Peronpicricus, Bennett (1830). 
Perodicticus, Bennett, P. Z. S. 1830, p. 109; Van der Hoeven, 
Tijds. pp. 20, 40; Wagner, Schreber, Suppl. i. p. 288, v. p. 152; 
Dahlb. Studia Zool. p. 207; A. Smith, S. Afr. Journ. (1835) 11. p. 30; 
Murray, Proc. R. Phys. Soc. Edinb. 1860, p. 191; Gray, P. Z. 8. 
1863, p. 150; Huxley, P. Z. 8. 1864, p. 335. 
Characters.—Index finger rudimentary and nailless; tail rudi- 
mentary, but distinct ; upper incisors large, subequal; first upper 
premolar very long; last upper molar bicuspid; last lower molar 
quadricuspid ; palate not produced*; premaxille not projecting 
much forwards; dorsal vertebree fourteen or fifteen ; lumbar verte- 
bree seven or eight. 
Hab, West Africa: Sierra Leone. 
Genus 4. Arcrocerus, Gray (1863). 
Arctocebus, Gray, P, Z.S. 1863, p. 150; Huxley, P. Z. 8. 1864, 
p- 330. 
Perodicticus, Smith, Proc. R. Phys. Soc. Edinb. (1860) p. 172. 
Characters.—Index finger rudimentary and nailless; tail rudi- 
mentary ; upper incisors small and subequal ; first upper premolar 
short, very little exceeding the second in vertical extent ; last upper 
molar tricuspid; last lower molar quinquecuspid ; palate scarcely 
produced beyond the last molar; dorsal vertebree fifteen ; lumbar 
vertebrze seven. 
Hab. West Africa: Old Calabar. 
The skeleton of the type of the genus is preserved in the Museum 
of the Royal College of Surgeons. 
* In pl. 1. fig. 2 of F. A. W. Van Campen’s “ Monograph on the Anatomy of 
the Potto” (Verhand. der Koninkl. Akad. yan Wetenschappen, 1859, deel vii.) 
the palate appears, as I have found it, unprolonged. However, in Van der 
Hoeven’s ‘ Bijdrage tot de Kennis van den Potto,’ 1851, pl. 2. fig. 3, the palate is 
represented as prolonged considerably beyond the last molar. 
