Explanation of the Plates. 



Plate 12. 



Fig. 1. Outer surface of the left Human scajjula. 

 " 2. Inner " " " " " " 



" 3. Anterior view of the left Human humerus. 

 " 4. Posterior " " " " 



Plate 13. 



Fig. 1. Anterior view of the left shoulder-girdle of a Chelonian [Ptychemys nnjosa). 



The upper end of the scapula points downward in the figure. 

 Fig. 2. Posterior view of the same. 



Fig. 3. Left humerus ; showing the ulnar side of the upper half of the bone. 

 Fig. 4. Left humerus ; showing the radial side of the upper half of tlie Ijonc. 

 Fig. 5. Superior view of the left shoulder-girdle of the same. 

 Fig. 6. Inferior view of the same. 

 Fig. 7. Dorsal view of tlie left humerus of the same. 



Explanation of the Figures. 



The dotted lines mark out the areas of attachment of the several muscles to the 



bones. The round dots, thus , are used to define the areas of origin, and the 



elongated ones, thus , are used to define the areas of insertion. 



In the following list the names in tlie first row are those in common use in anthro- 

 potomy ; those in the second row are names applied by various authors to correspond- 

 ing parts in Chelonians. 



Tlie same numbers are used in both plates to designate parts, or areas, considered to 

 be homologous. 



M. teres major. 



M. latissimus dorsi. 



1. Musculus teres major, 



2. " latissiTnus dorsi, 



3. " teres minor, 



4. " infraspinatus, 



5. " deltoideus, 



6. " supraspinatus, 



7. " coraco-brachialis, 



8. " subscapularis. 



9. " biceps, 



10. " omoliyoideus, 



11. " triceps, 



12. M. serratus magnus. 

 121). M. piectoralis minor. 



M. deltoideus. 



\ Gh, M. claviculo-hrachialis Riid. 

 ( ()(t, M. coraco-brachialis propirius anticus Riid. 

 M. coraco-brachialis Riid. 

 8a, f M. subscapularis Riid. 



M. clamculo-hrachialis Boj. 

 M. supraspnnatus, anon. 

 I (^ M. subscapularis Oken. 

 (^ 8&, M. infi-asjmiatus Riid. 

 M. biceps brachii Riid. 

 M. coraco-hyoideus Riid., omohyoideus Boj. 

 11a, 11&, M. triceps brachii. 

 j pars M. serratus anticus major Riid. 

 \ S. M. costo-scajmlaris Riid. 

 i j)ars M. serratus anticus major Riid. 

 12&. ■< S. M. costo-coracoideus Riid. 

 ( S. M. pectoralis minor Riid. 

 i pars M. serratus anticus major Riid. 

 12c. -| S M. subclaveus Riid. . 

 f S. M. costo-clavicularis Riid. 



12a 



13. muscidus pectoralis major. 

 14. 



a, 



b, 



c. 



trapezius. 

 Acromion process of scapula. a 

 Axillary border " " b 



Coracoid process " " c 



Spine " " 



Glenoid cavity " " 

 Coraco-acromial ligament. 

 "Radial," or "greater" tuberosity. 



"Ulnar," or "lesser 

 Head of humerus. 



tuberosity. 



acromion. 



scap)ula. 



coracoid. 



■ Radial," " lesser," or ' 



the liumerus. 

 'Ulnar," "greater," or 



' outer " tuberosity of 

 "inner" tuberosity. 



