CiiAP. I. THE MUSCLES. 273 



processus transversus, or as a first riuliincntar}- rib,) and from tlie dorsal shield 

 in its neighborhood, going to the scapula and drawing it backwards. This muscle 

 is the M. subclavius or retractor scapulce of Bojanus. A third muscle is extended 

 between the tongue-bone and the coracoid, the M. coracohyoideus. Besides this 

 muscle, which originates from the lower side of the bony framework of the tongue- 

 bone, we find for the tongue two other pairs of muscles, the musculi hyothyreoidei 

 and the musculi cricoarytajnoidei. 



The muscular apparatus of the extremities is remarkable for its similarity to 

 that of Mammalia.' In place of the M. pectoralis major, we find two muscles, 

 one originating from the middle part of the sternum and attached to the tuberosity 

 of the humerus, whence it spreads downwards over the arm and the forearm, and 

 another, much weaker, arising from the anterior part of the sternum and attached to 

 the same internal tuberosity. The deltoid muscle originates from the end of the 

 acromion and goes to the same tubercle. The muscles arising from the scapula, 

 the M. subscapularis and the M. teres, are both attached to or near the tuberculum 

 externum. A muscle corresponding to the M. latissimus dorsi, arising from the 

 exterior lateral part of the dorsal shield, is attached to a little cavity inside of 

 the tuberculum externum. The M. coracobrachialls, arising from the coracoid and 

 attached to the tuberculum externum of the humerus, is simple in the family of 

 Emydoidie, and double, as in Mammalia, in the Trionychida^. The muscles of the 

 forearm, and those of the hand and fingers, are essentially identical with those of 

 the Saurians; the degree of development of the muscular apparatus of the hand and 

 fingers varies much, however, in different families. They are much less developed 

 jn the sea and land Turtles than in the Avebfooted EmydoidjB, Cinosternoidae, 

 Chelydroida?, and Trionychida?. The characteristic muscles of the hind extremities 

 are the following: two musculi gluta2i, (a major and a minor,) originating from 

 the OS ilii and from the seventh rib. Forming at first one muscle, they are soon 

 divided into two branches, one of which is attached to the trochanter, the other 

 to the femur itself The M. biceps, originating from the os ilii, is in.serted upon 

 the fibula. The M. psoas, originating from the last vertebra of the back, before 

 the sacrum, is attached to the upper part of the femur. The Musculi adductores 

 femoris originate, one from the symphysis ischiadiea, another from the os pubis, 

 and a third from tlie membrana obturatoria and from the anterior margin of the 

 OS ischii. 



' Its (1<!V(l()pni(nt, liowever, is voiy tliffercnt lil)iium : wliile in sea Turtles, in wliii'li the fnre 



in different families. The fore legs anil the hind legs are the chief locomotive organs while the hind 



legs have an equally strong muscular apparatus in legs serve almost only as rudders, the fore legs 



land Turtles, where the whole body stands in equi- have a much larger muscidar development. 



35 



