MAMMALS. 385 



dont marsupials, the creodont carnivores, and the lemurs. They 

 inhabit to-day only the old world and North America ; while the 

 fossils occur only in the northern hemisphere, where they date 

 back to the eocene. The order is one of the most primitive of 

 the placental mammals ; but as yet the fossils are too few and 

 too imperfectly preserved to allow the complete working out of 

 the lines of descent. As here limited the order includes only 

 the Insectivora Vera. By some writers the galago, Gateopithecus, 

 of the East Indies (seep. 415) is included in a second sub-order, 

 Dermaptera. 



The ICTOPSID^E, from the American eocene and miocene, have skulls 

 much like the hedgehogs, but a simpler dental pattern. The ADAPISORI- 

 CID,E take their place in the eocene of France. The TALPID^E, or moles, 

 with / | to f, c \, PHI % to f , ;// f , snout elongate, tympanic bulla present ; 

 fore limbs modified for digging, with a sesamoid bone (os falciforme) on the 

 radial side ; tibia and fibula united ; are small burrowing animals, of which 

 Talpa is the typical genus, with / f , c \, p |, m f . The species of Talpa 

 belong to the temperate part of the old world. In America occur the 

 genera Scalops, with 36 teeth, and Condylura, the star-nosed mole, with 44 

 teeth. Talpa dates from the miocene, Talpavus from the miocene. Allied 

 are the MYOGALID.E, in which the falciform bone is absent. Urotrichus, 

 the mole shrew, is the only North American genus. In the TUPAIID^E, in 

 which the lower incisors are never less than two, the tibia and fibula are 

 distinct, and the orbit is encircled by bone. The species are oriental in 

 their distribution, and have arboreal habits. Titpaia. Galerix, from the 

 European eocene. The shrews (SORICID^E), which appear in the eocene, 

 are distributed through the northern hemisphere. They lack the postorbital 

 process, have tibia and fibula fused, and no zygomatic arch ; teeth i \ to f , 

 c ^, p ^-, m \. Sorex\s represented by many species in both hemispheres. 

 Blarina is American. Crocidura, Nectogale. The DIMYLID.E includes 

 miocene species. In the ERINACEID^E, or hedgehogs, the dorsal surface 

 is covered with spines or bristles. All of the species belong to the old 

 world, and are terrestrial and nocturnal. The hedgehogs belong to Erina- 

 cens, a genus which appears in the miocene. The species of MACROSCEL- 

 ID/E from Africa are known as the jumping shrews, from their kangaroo-like 

 gait. The SOLENODONTID^E from the West Indies are remarkable for having 

 the mammae on the buttocks. The tenrecs (CENTETID.E) are from Mada- 

 gascar. The golden moles (CHRYSOCHLORID/E) of Africa have the hair of a 

 brilliant metallic lustre, bronze, green, or violet in color ; the eyes are cov- 

 ered by the integument, and the external ears are concealed by the fur. The 

 last four families have no fossil representatives, but are nearest in structure 

 to the Ictopsidas. 



