238 



MR. O. E. DOBSON ON CAPROMYS MEI-ANTTRUS. 



Apr. 1, 



backwards, divides near its insertion into three slips, of which the 

 two superficial (r, r,-r , r' n ) interdigitnte with those of the muscles 

 of the opposite side, and are inserted into the symphysis pubis on 

 the side opposite to those from which the muscle is derived ; the 

 third slip (r 3 -r' 3 ) passes directlv to its insertion into the correspond- 

 ing; side of the symphysis pubis, close to its fellow of the opposite 

 side. The arrangement of the interlacing slips is as follows : — The 

 most superficial slip (r) is derived from the left rectus ; this crosses 

 a slip ()•') from the superficial surface of the right rectus and is 

 inserted into the right side of the symphysis pubis, while the latter 

 (r') passes to the left side ; the next slip is the second (r 2 ) from the 



Fie;. 2. 



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Semi-diagrammatic, showing the relative portions of the intersecting slips of 

 the right and left recti abdominis and of the obliqui extern* muscles near 

 their attachments to the pubic bones. 



left rectus, proceeding to its insertion into the right side of the 

 symphysis under cover of the first slip (r), while the deepest of the 

 interdigitating slips is the second (r' 2 ) from the right rectus, which 

 passes to its insertion into the left side of the symphysis under cover 

 of the first from the same muscle. 



Obliquus externus, obliquus interims, transversalis. — These muscles 

 present no peculiarities. No blending together of the obliqui externi 

 with the recti, as described by Prof. Owen in G. pilorides (P. Z. S. 

 1832, p. 74) was found in this species ; the internal fibres (o) of the 

 first-named muscles are inserted into the symphysis pubis, under 

 cover of and slightly external to those of the deep interdigitating 

 slips of the recti, as shown in figure 2. 



Muscles of the Back, Thorax, and Abdomen. 



Trapezius anticus (fig. 1, t.a) arises from the inner third of 

 the occipital crest, from the centre line of the neck, and from three 

 or four dorsal spines, and is inserted along the spine of the scapula 

 to the end of the acromion, and into the outer third or more of the 



