of the Koala (Plia.scolarctos cinereus). 131 



their respective metacarpal bones. The extensor secundus 

 digitorum was attached to the fourth and fifth fingers. The 

 other extensors of the fingers, uhiar carpal extensor and extensor 

 sccundi inter nodii jwlUcis^ are as usual. 



The abductor 2)ollicis onajor has a radio-interosseal origin 

 and a double tendon of insertion into the trapezium and first 

 metacarpal. The left indicator sent a filmy slip to the pollcx. 

 There is a separate extensor medii digiti, with an ulnar origin. 

 The proportions of these muscles arc as follows : — flexors of 

 the wrist (/. c. r.^j^- ^-if- ^- '^'^O • extensors of wrist (e. c. r. I. 

 & &., e. c. id.) : : 0"36 : 0*75 ; flexors of fingers (/. d. s., 

 /. d.p.) : extensors (e. d. c, e. d. s., e. oss. to.jij,, e. s. int.p.^ e. i,^ 

 \.m.d.) :: 0'21 : 0-36. 



The hand-muscles are as follows : — For the pollcx, an 

 abductor brevis, a single-headed flexor , an opponens^ and an 

 adductor (from the third metacarpal). For the little finger 

 there are the following muscles : — abductor ^ opponens^ and 

 flexor muscles. The dorsal interossei are (1) a two-headed 

 abductor indicisj (2) a two-headed abductor mediij (3) a bici- 

 pital abductor medii^ (4) an cdiductor quarti digiti ; the 

 palmar interossei are (1) an adductor indicts from the second 

 metacarpal under the adductor p>ollicisj (2) a common adductor 

 of the third and fourth digits. 



There is no scalenus anticus | the medius is attached to the 

 first rib and to the fourth to the seventh vertebree ; the posticus 

 from the fifth transverse process to the third rib. Longus colli 

 consists of three parts — one from the bodies of the upper five 

 dorsal vertebras to the cervical transverse processes, a second 

 part from the transverse processes of the fourth to the seventh 

 cervical vertebra extending to the cervical bodies (second to 

 fifth) , and a third from the same origin to the occiput. 



The external oblique is attached to the ribs from the third to 

 the eleventh ; the internal oblique and transversalis are with 

 very great difficulty separable. The rectus abdominis has eight 

 lineas transversaj intersecting it, and is attached to the xiphi- 

 sternum and to the cartilages of the second to the sixth ribs. 

 Pyramidalis is very wide, covers the entire of the rectus^ and is 

 attached to the linea alba. The lumbar, vertebrse, besides the 

 ordinary quadratus luinborum (with its three usual component 

 parts), have attached to them anterior intertransversalesj most 

 of whose fibres skip two vertebrae. 1^\\q, psoas ixirvus is equal 

 to the psoas inagnus and 0'37 times the size of the combined 

 psoas magnus and iliacus^ whose elements are imperfectly sepa- 

 rable ; the latter part of this mass is bipartite, the portion most 

 closely united to the psoas magnus being separate from a part 

 of the muscle arising from the anterior superior iliac spine. 



