386 



ANATOMY OF VERTEBRATES. 



In the burrowing Mole, fig. 248, the first sternal bone, or 

 manubrium, is of unusual length, being much produced forward, 

 and its under surface downward in the shape of a deep keel for 

 extending the origin of the pectoral muscles. Seven pairs of 

 ribs directly join the sternum, which consists of four bones, in 



248 



i 'i \[\\\^-^ 



Mole (Talpa europwa). 



249 



addition to the manubrium and an ossified ensiform appen- 

 dage. The neural spines, which are almost obsolete in the first 

 eight dorsals, rapidly gain length in the rest, and are antro- 

 verted in the last two dorsal vertebrae. The diapophyses, being 

 developed in the posterior dorsals, determine the nature of the 

 longer homologous processes in the lumbar vertebras. In these 

 the neural spines are low, but of considerable antero-posterior 

 extent : the diapophyses are bent forward in 

 the last four vertebrae : a small, detached, 

 wedge-shaped hypapophysis, fig. 249, C, «, is 

 fixed into the lower interspace of the bodies 

 of these vertebras. 



The ossa innominata have coalesced with the 

 sacrum, fig. 248, s, but not with each other, the 

 l^ubic arch, 64, remaining open. The bodies of 

 the sacral vertebras are blended too-ether and 

 are carinate below : their neural spines have 

 coalesced to form a high ridge. The acetabula 

 look almost directly outward. In the cervi- 

 cal series tlie odontoid process shows a sharp hypapophysis : 

 the neural spine of the dentata, fig. 249, a, 2, is large and ex- 

 tended back over the third vertebra : the neural arches of this 

 and the succeeding vertebrae form, above the zygapophyses, thin 

 simple arches, without spines; the transverse processes of the 

 fourth, fifth, and sixth cervicals are produced forward and back- 

 ward, and overlap each other, ib. 4—6 : in the seventh those 



A, B, cervicals, c, lurabars 

 of Mole. LXXXVI-. 



