1892.] MUSCULAR ANATOMY OF AULACODUS. 523 



Gastrocnemius by a muscular insertion ; it recalls the femoro-caudal 

 of Birds. 



The Semitendinosus arises by two heads ; its flat strap-shaped 

 tendinous insertion on to the tibia commences just after that of the 

 gracilis. 



The Gluteeus medius is a powerful muscle hardly to be dis- 

 tinguished at its origin from the Gluiceus minimus ; it is inserted 

 along the lower margin of the femur in front of the great trochanter 

 for a distance of 30 mm. ; the insertion is partly muscular and 

 partly tendinous ; the tendinous part of the insertion is divided up 

 into a number of more or less distinct tendinous insertions. 



The Gluteeus minimus is a powerful muscle difficult to distinguish 

 from the last at its origin ; it arises from the greater part of the 

 ilium ; it becomes quite separate from the Gluteeus medius a little 

 before the insertion on to the great trochanter. 



There was no trace that I could discover of a Scansorius, whose 

 presence is mentioned in several Rodents. 



The Adductor magnus is not by any means a large muscle ; it is 

 quite distinct from the other adductors ; it is long and thinnish, 

 and arises from the symphysis pubis by a tendinous origin ; the 

 upper surface of the muscle is glistening for a considerable distance 

 after the origin. 



The other two Adductors form a large fleshy mass and are not 

 readily distinguishable from each other. 



The Iliacus is a large muscle divided into two portions; it is 

 inserted together with the Psoas on to the lesser trochanter. 



The Psoas magnus is a large muscle, also divisible into two parts ; 

 the part which arises most anteriorly becomes tendinous on one side 

 a couple of inches from its insertion. 



The Pyrifoi'mis is present. 



Both Obturators were present. 



The Rectus femoris originates by two well-defined heads, which 

 are tendinous, though overlaid by muscular fibres ; the muscle is 

 covered anteriorly by the Vastus externus. 



The Gast7'ocnemius has the usual two heads, which take origin 

 from two sesamoids ; the inner head is the smaller of the two. 



The Plantaris arises in common with the outer head of the last, 

 and is fused with it for some way ; it splits into three tendons on 

 the sole of the foot. 



The Soleus is fleshy with a tendinous origin from the head of 

 the fibula; its exposed surface is glistening; it is inserted on to 

 the OS calcis. 



The tendons of the Fleooores tibialis and fhularis join before the 

 latter splits into its four tendons of insertion : the tendon of the 

 Flexor tibialis seems to be mainly concerned with the supply of the 

 inner of the four tendons ; the fourth of the four tendons of the 

 Flexor fibularis is very much smaller than the rest, which is of 

 course in relation to the comparatively rudimentary fifth toe ; this 

 tendon arises from the lower surface of the conjoined tendons and 

 not from the outer edge. 



