170 MR. v. a. PABSONS ON TUB [Jail. 14, 



EpitrocMeo-ancotwus. — This is present in all the Myomorpha ; it 

 is supplied by the ulnar nerve. 



Pronator Itadii Teres. — This muscle agrees with the description 

 given of it in other liodents ; in Mas harbarns and Oricetus it is 

 inserted into the second quarter of the radius, while in all the 

 other animals examined it goes into the middle of that bone. 

 Oricelomys resembles Sciarus in possessing a supracondylar 

 foramen, but in it the pronator teres does not rise from the supra- 

 condylar arch, as it does in Sciurus. 



Flexor Carpi Hadialis. — The attachments of this muscle were 

 normal in all cases. In the Vole, and, to a lesser extent, in all 

 Eodents, the tendon of this muscle is bound down to the flexor 

 surface of the radius by a fibrous pulley just below the attachment 

 of the pronator radii teres. 



Palmuris Longus. — The muscle is present and large in Cricetomys, 

 Gricetus, Microtus, Oeorychus, Bathyeryus, Mus rattus, Siphneus, 

 and Ifeteromys ; it is inserted into the palmar cartilage or ossicle 

 and into the fascia of the palm. In Ithizomys and Qerbilliis it 

 is only inserted into the fascia, while in Myoxtis it is absent. 

 In Mits harbai-us it is developed as a slip from the surface of the 

 flexor sublimis digitorum, an arrangement which recalls that found 

 in Coeloyenys and Xervs. 



Flexor Sublimis Biyitorum. — In all the animals examined, except 

 Myoxus, this muscle rises from the internal condyle and forms 

 the flexor perforatus for tlie 2nd, 3rd, and 4th digits. In Myoxus 

 it also goes to the 5th digit. Milne-Edwards describes the slip 

 to the 2nd digit as a distinct muscle in Siphneus. 



Flexor Carpi Vlnaris. — This muscle has the usual attachments, 

 except that in llhizomys and Baihyergus the origin from the 

 internal condyle is wanting. The tendon is specially thiclc in 

 Oeonicliiis. 



Flexor Profundus Digitorum. — The deep flexor of the fingers is 

 composed, as in other Kodents, of two superficial heads from the 

 internal condyle and of two deep heads from the flexor surfaces 

 of the radius and ulna. A small slip is given off to the pollex 

 from the front of the teudon formed by these heads in Cricetomys, 

 Gerbdlus, Microtus, Mus barbarus and rattus, Myodes, Georychus, 

 Bathyergus, and llhizomys. In Myoxus, Gricetus, and Siphneus 

 (Milne-Edwards) no tendon goes to the thumb. In Baihyergus 

 the fibres derived from the different heads were traced downward 

 through the tendon, and it was found that the two condylar 

 heads join together to form the superficial part of the tendon, 

 which gradually winds round the outer side to eventually become 

 deep. When the tendon divides into its ultimate five slips for 

 the four fingers and the thumb, each slip receives fibres both from 

 the condylar and the radio-ulnar origins. This twisting of the 

 tendon reminds one of the arrangement of the fibres of the tendo 

 Achillis '. There are usually four lumbricals which arise from 

 the flexor surface of the tendon at or before its point of division. 

 ' Author'a paper, ' Journ. AniU.' vol. xKvii. p. 414. 



