438 



THE RABBIT. PHYLUM CHORDATA 



wrist is a small membrane bone, the pisiform. A membrane 

 bone, the knee-cap or patella, covers the knee joint and is con- 

 nected by ligament with the tibia. The tibia and fibula are fused 



at their lower ends. The first 

 row of tarsals contains two 

 prominent bones, the astragalus 

 or talus, and the fibulare or 

 calcaneum, which lies outside 

 the astragalus and projects 

 backwards to form the heel. 



cor.f.-H-, 



tro. --\- 



y.aap.-r. 



l^J^-CUXp.lJ^. 



7TVC! 



True.' 



ALIMENTARY SYSTEM : 



MOUTH, TEETH, AND 



PHARYNX 



The mouth differs from that 

 of the frog in the possession of 

 mobile, muscular lips, and of a 

 palate — an inner roof which 

 separates from the mouth or 

 buccal cavity a narial passage. 

 By this passage the approach 

 from the nostrils to the mouth 

 is prolonged backwards, so that 

 the internal nares open into the 

 pharynx instead of into the 

 forepart of the mouth (Fig. 350). 

 The first part of the inner roof 

 is strengthened by the horizontal 

 processes of the premaxillary, 

 maxillary, and palatine bones 

 (p. 429) and is know^n as the 

 hard palate ; the hinder part is 

 purely fleshy and is known as 

 the soft palate. The narial pas- 

 sage lies above the palate 

 and below the true olfactory 

 chambers. Over the hard palate it is not separated from these by 

 any roof, and the nasal septum between them comes down to 

 divide it into two (p. 427). Over the soft palate it is single, and is 

 separated from the olfactory chambers by a partition, supported 



Fig. 349. 



-Bones of the left fore- 

 limb of man. 



A, In pronation ; B, in supination. 



c.i, Os multangulare majus or trapezium ; c.2, 

 multangulare minus or trapezoid ; c.3, 

 capitatum or magnum ; c*, hamatum or 

 unciform; cap., capitulum of the 

 humerus, with which the rc.dius articulates; 

 cap.r., capitulum cf the radius ; cap.u., 

 capitulum of the ulna ; cor.f., coronoid 

 fossa ; hu., humerus ; im., os lunare or 

 semilunar ; mcA, mc.^, first and fifth 

 metacarpals ; pi., pisiform ; r.c, os navi- 

 culare or scaphoid ; ra., radius ; ra.f., 

 radial fossa ; st.p.r., styloid process of the 

 radius ; tro., trochlea ; u.c, os triquetrum 

 or cuneiform ; ul. ulna. 



