1898.] ANATOMY or PEDETES CAEFEE. 865 



extremity receives the insertion of the tendon of the flexor tibialis. 

 From its position I think that it may correspond vrith the radial 

 ossicle in the manus, though it is connected with the distal row of 

 tarsals instead of the proximal. A ligament runs forward from 

 the anterior part of its lower extremity and connects it with the 

 dorsal extensor tendon. In Bipus, as is well known, the three 

 middle metatarsals are fused, hut on the inner and outer side are 

 rudiments of the first and fifth metatarsals, the former being 

 continuous with the internal cuneiform. In the foetal Pedetes 

 there are centres for the calcaneum and for the shafts of the four 

 metatarsals and their phalanges. 



The Muscular System. 



In former volumes of the Proceedings of this Society ' I have 

 described the muscles of a considerable number of Eod^nts. I 

 shall therefore content myself with noticing the chief points in 

 which Pedetes agrees with or differs from the typical arrangement. 



The Temporal is very small and does not meet its fellow in the 

 mid line of the skull. 



The Masseter has the typical hystricomorphine arrangement ; 

 the anterior deep part is very large as in all the Hystricomorpha 

 and Dipodidse. 



The Facial Muscles consist of orbicularis palpebrarum, orbicu- 

 laris oris, levator labii superioris, retractor and depressor naris, 

 depressor anguli oris : there is also a muscle which rises from the 

 malar bone beneath the orbit and deep to the orbicularis palpe- 

 brarum ; it passes round the chin like a chin-strap, and is inserted 

 into the skin of that region ; its fibres are parallel \\it\i and in 

 the same plane as those of the sphincter colli, and it is the only 

 representative of the zygomaticus to be found. 



The Depressor Mandihulcn (Digastric) has the typical sciuro- 

 morphine and myomorphine arrangement (figured on p. 255, 

 P. Z. S. 1894), and in this agrees with the Dipodidse. 



The Transversus Mandibulce is absent, but is present in the 

 Dipodidse. 



The Sterno-mastoid rises from the presternum and is inserted 

 by tendon into the paroccipital process. 



The Cleido-mastoid rises from the inner half of the clavicle and 

 is inserted by flesh into the paroccipital process and occipital 

 crest. As in all Eodents the Xlth nerve passes deep to both 

 muscles. 



The Sterno-hiioid and Sterno-tJvjroid are distinct and have the 

 usual human attachments. No tendinous intersection was seen. 



The Omo-Jiyoid was absent. It is always present in the Sciuro- 

 morpha, Myomorpha, and Dipodidse. 



The Omo-trachelian (Levator claviculse) rises from the anterior 

 arch of the atlas and is inserted into the metacromion deep to the 

 trapezius. 



' P. Z. S. 189i and 1896. 



