322 PBOF. r. G. PARSONS OS THE 



Flexor Longus Guhiti (Biceps). — This muscle has both heads 

 ■well developed, it is inserted into the radius. 



Flexor Brevis Cuhiti {Qova.co-hva,c\\idl\^\ — The frequency with 

 which all three parts of this muscle are present seems to be one 

 of the characteristics of sciuromorphine rodents, and Anomalurus 

 is no exception to this rule. The three parts are closely blended 

 near their origin, and the upper part or rotator humeri is sepa- 

 rated from the middle, as is usual, by the musculo-cutaneous 

 nerve. The middle and lower portions (medius and longus) are 

 closely united in their whole extent and are inserted from the 

 upper third of the humerus as far as the internal condyle. 



Goraco-patagialis. — A muscle with a small short fusiform belly 

 and a long delicate tendon rises from the coracoid process, and 

 is inserted into the patagium midway between the spur from the 

 elbow and the trunk. Its action seems to be to act as a stay to 

 the membrane, and keep its edge down during flight, thus 

 rendering the part of the patagium between the arm and the 

 body more concave and parachute-like. As I have never seen 

 anything homologous with this muscle in other mammals, I have 

 suggested the name " coraco-patagialis " for it. 



Brachialis anticus. — This muscle resembles that of most sciuro- 

 morphine rodents in having the inner and outer heads so closely 

 connected as to be inseparable. 



The Extensor Cuhiti (Triceps), Anconeus, and EpitrocJileo- 

 anconeus call for no special remark. 



Latissimo-olecranaJis (Dorso-epitrochlearis). — This rises from 

 the tendon of the latissimus dorsi as well as from tiiat of the 

 teres major. It is inserted into the inner side of the olecranon 

 process. 



Serratus ventralis (Serratus magnus and Levator anguli 

 scapulae). — This continuous sheet rises from the transverse pro- 

 cesses of the posterior five cervical vertebrae and from the anterior 

 ten ribs ; it is inserted as usual into the vertebral border of the 

 scapula. I only know two other rodents, Georychus and Bathy- 

 ergus, in which the rib origin is so extensive. 



The Pronator Badii Teres is inserted below the middle of the 

 radius ; it rises, as in Sciurus and Bteromys, from the lower part 

 of the arch over the supracondylar foramen. 



The Flexor Garpi Badialis and Palmaris Longus have the usual 

 human attachments and relations. 



