612 INSECTIVORA 



chloris to 6 in Talpa and Sorex ; and of the caudal from the rudi- 

 mentary series of 8 in Centetes to the 40 or more of Microgale. Xot 

 less variable are the characters of the vertebrae themselves ; the 

 spinous processes often being very long in one and short in another 

 species of the same genus. In the Soricidce and Myogale the neural 

 arches of the cervical vertebrae are very slender. In the Soricidce 

 and Gymnura the four anterior vertebrae develop large single hypa- 

 pophyses. In Galeopithecus the centrum of each vertebra supports 

 posteriorly a pair of intercentral ossifications ; while in Erinaceus, 

 Myogale, and Talpa small oval ossicles are found on the inferior 

 surfaces of the lumbar interspaces. In Erinaceus, owing to the 

 thickness of the neural cord in the cervical region and its abrupt 

 termination, the diameter of the neural canal in the cervical and 

 first two dorsal vertebrae greatly exceeds that of any of the succeed- 

 ing vertebrae. The sternum is variable, but generally narrow, 

 bilobate in front, and divided into segments. The pectoral girdle 

 presents some remarkable adaptive modifications, most fully ex- 

 pressed in Talpa, having relation to the use of the fore limbs in 

 burrowing; but in the Golden Moles (Chrysochloris) the forearm 

 and manus alone become specially modified for this purpose. In 

 Galeopithecus and Macroscelides the bones of the forearm (radius 

 and ulna) are distally united. The manus has generally five digits, 

 but in Rhynchocyon and in one species of Oryzorictes the pollex is 

 wanting, while in the true Moles it is extremely modified. The 

 femur has, in most species, a prominent ridge below the greater 

 trochanter representing a third trochanter. In Galeopithecus, Tupaia, 

 Centetes, Hemicentetes, Ericulus, and Solenodon the tibia and fibula 

 are distinct, but in all the other genera more or less united 

 together. The pes usually possesses five digits (rarely four by 

 reduction of the hallux) ; and in some forms, as in the leaping 

 species (Macroscelides, Rhynchocyon}, the tarsal bones are greatly 

 elongated. The form of the pelvis, and especially of the sym- 

 physis pubis, varies within certain limits; and these differences 

 have been proposed by Leche as a basis for the classification of the 

 families. Thus in the Galeopithecidce, Tupaiidce, and Macroscelididce 

 there is a long symphysis ; in the Erinaceidce, Centetidce, and Potamo- 

 galidce the symphysis is short; and in the Soiicidce, Talpidce, and 

 Chrysochloiidce there is none. 



Space does not admit of attempting a sketch of the modifica- 

 tions of the muscular system, which will be found fully described 

 in Dr. Dobson's Monograph, referred to in the bibliography. As to 

 the nervous system, it has been already mentioned that the brain 

 throughout the order presents a low type of organisation ; in none 

 of the members do the cerebral hemispheres present any trace of 

 convolutions, nor do they extend backwards so as to cover the 

 cerebellum, while the olfactory lobes are large and project in front, 



