In dilambdodont molars the primitive crest between paracone and metacone (centrocrista) is represented by a pair of crests that join the mesostyle (postparacrista, premetacrista). The cutting action of these crests against the crests of the hypoconid is described. Dilambdodonty is a derived adaptation for greater cutting efficiency. It has evolved several times and in more than one way. 

The East African Miocene Macroscelidea, lnsectivora and Chiroptera are revised on the basis of new material. New taxa proposed are: Miorhynchocyon, .n. gen. (Macroscelididae): Míorhynchocyon meswae, n. sp.: Pronasílío ternanensis. n. gen.. n. sp. (Macroscelididae); Hiwegicyon juvenalis, n. gen. n. sp. (Macroscelididae); Parageogale, n. gen. (Tenrecidae): Prochrysochlorinae, n. subfam. (Chrysochloridae): Propottininae, n. subfam, (Pteropodidae); Chamtwaria pickfordi, n. gen., n. sp. (Vespertilionidae). Gymnurechnínus songhorensis is synonymised with G. camptolophus. The new material provides additional information on the dentition, especially of Myohyrax oswaldi. Galerix africanus. Amphechínus rusingensis, Protenrec tricuspis and Parageogale aletris. Partial skulls are described of Amphechinus rusingensis, Protenrec tricuspis, Prochrysochloris míocaenicus and Taphozous incognita. The oldest member of the Macroscelidinae (Pronasilio) is described from Fort Ternan. Galerix africanus is closely related to G. exilis from Europe. Amphechinus rusingenesis is compared with Asiatic Oligocene Erinaceinae. The Miocene age of Crocidura is rejected. On the evidence of humeri, the following families of Chiroptera are newly reported: Pteropodidae, Nycterididae, Vespertilionidae, Molossidae. Propotto is regarded as an offshoot from the Pteropodidae, not ancestral to modern forms. Chamtwaria is a primitive vespertilionoid, provisionally placed in the Kerivoulinae. Erinaceidae probably entered Africa at the beginning of the Miocene, before 20 Ma. Faunistic differences between deposits are largely to be ascribed to differences in local environment. 

The wear facets of primitive rodents can be homologized with those of primitive primates and ungulates. As in primates, the jaw movement was ectental, with an increased anterior component in the lingual phase (phase ll). The buccal phase (phase I) in rodents approaches the horizontal and it tends to be reduced in importance in comparison with the lingual phase. ln more advanced rodents the efficiency of grinding is increased by the development of additional cutting edges of enamel (e.g. enlargement of hypocone, development of mesoloph and lingual sinus). The buccal phase movement becomes lined up with the lingual phase movement to form a single oblique chewing stroke,resulting in planation of the crown. As the stroke becomes more longitudinal (propalinal) the enamel edges become more transverse. In Muridae propalinal chewing evolved before the loss of cusps, facets were reorientated and additional cusps developed.