18 MESSRS. F. E. BEDDARD AND F. TREVES ON THE [Jail. 15, 



Hyrax possesses in addition an extensor carpi ulnaris, which is 

 wanting in the Ungulates. 



In Hyrax the extensores primi, secundi internodii, and indicis are 

 wanting, which is so far a resemblance to the Ungulate in that the 

 last two of these muscles are present in the Rabbit^ and apparently 

 in Hydromys. 



The supinator longtis, which we have described in the Rhinoceros, 

 is absent in the Horse, and according to Meckel, quoted by Messrs. 

 Murie and Mivart, in many Rodents. Wiudle^ asserts its absence in 

 Hydromys, and Huxley in the Rabbit. Its presence in Hyrax is 

 therefore of particular interest and also its presence in the Tapir. 



Muscles of the Hind Limbs (figs. 6, 7, 8, 9). 



Iliacus. — This mnscle is largely tendinous upon the inner side; 

 its origin is from tlie whole of the iliac fossa. 



Psoas. — A small muscle dividing into two tendons ; both are 

 inserted into lesser trochanter, cuiTing round femur from before 

 back. 



Psoas parvus.— The upper part of the belly is muscular but 

 soon becomes tendinous ; it is continuous with the sartorius (see 

 fig- 7). 



Gracilis. — The gracilis is enormously wide and muscular through- 

 out ; it arises from pubic arch and is inserted by a large muscular 

 and tendinous insertion into fascia above the inner side of the knee, 

 which is continued on to patella and then on to inner side of tibia. 



Pectineus is a fleshy, somewhat fiat oblong-shaped muscle ; it 

 arises from pubis along pectineal line ; it is inserted on to the femur 

 as in the Horse. 



Adductor lonyvs. — Arises from ramus of pubis, where it is blended 

 with adductor magnus ; its insertion is the same as that of the 

 gracilis, except that it also is attached to the lower end of the femur ; 

 it is partly covered by gracilis. 



Adductor 7nugnus is a large fleshy muscle with but little tendon ; 

 its origin is muscular and it is here fused with adductor lortgus as 

 already stated ; its insertion is to inner side of shaft and to inner 

 condyle of femur ; it forms a tendinous arch for artery at juiKtion 

 of middle and lower third. 



The Rectus and two Fasti were fused into a single muscle, the 

 elements of which were indicated by ajioueuroses ; the muscle is 

 inserted on to patella. 



Semiiuembranoaus. — This muscle is unitt-d to form one muscle 

 with thesemitendinosus ; it is inserted by a flat tendon parallel with 

 and \ inch behind the crest of tibia ; this tendou is three inches 

 long. 



The Peronei muscles are four in number : — 



(1) Originates from the outer side of the liead of the fibula and 



' Huxley, ' Anatomv of Vertebrates,' p. 439. 

 P. Z. S. 1887, p. hiK. 



