THE PHOCID^. 



427 



flexor brevis, and opponens of the fiftli digit. A special long 

 abductor of tliis digit, however, passes from the olecranon to 

 the distal phalanx. The iliacus is wanting, and there is no 

 psoas major ; but muscles which represent the psoas minor 

 and the subvertebral muscles of the Cetacea are very large 

 and play an impoi'tant part in effecting the locomotion of the 

 Seal. The pectineus is very small, and the other adductors 

 are inserted, not into the femur, but into the tibia. The 

 glutceus maximus is inserted into the whole length of the 

 femur. The senii-membranosiis and semi-tendinosus are re- 

 placed by a caudo-tibialis, which arises from the anterior 

 caudal vertebrse and is inserted into the tibia, some of its 

 tendinous fibres extending to the plantai* aspect of the 

 hallux. The poplitceus and gastrocnemius are strong, but 

 there is no soIcbus. The tendon of the plantaris passes over 

 the calcaneum and ends on the plantar fascia of the per- 

 forated tendon of the fourth digit. The other perforated 

 tendons seem to arise from the fascia attached to the cal- 

 caneum. 



The dental formula is i. -—- c. - — - m.p.m. —-z - 34. 



The grinding teeth have triangular crowns with notched 

 edges, and at most two fangs. 



The milk teeth are shed during festal life, and at this 

 period there ai'e three molars above and below on each side, 

 which appear to be replaced by the second, third, and 

 fourth of the adult set. If such be the case, only the hinder- 

 most of these last will be a true molar. 



The tongue is bifid at the extremity. The oesophagus, 

 very wide and dilatable, passes without any very well 

 marked line of demarcation into the stomach, which is 

 a great pyrif orm sac with its pyloric end bent upon itself. 

 The intestine is about twelve times as long as the body. 

 The colon is short, and is provided with a coecum. The liver 

 is divided into a gi-eat number of lobules, which are, as it 

 were, set upon the inferior cava. The latter vessel, just below 

 the diaphragm, presents a great dilatation, into which 

 the wnoe hepaticce of the several lobules open. After tra- 



