172 DR. B. C. A. WINDLE AlfD MR, T. G. PARSOIfS ON THE [Mar. 1 , 



Peroneo-tibialis. — This muscle has beeu noticed by Gruber 

 (XLVIII.) as being present iu 24 out of 30 specimens of Canis 

 fatniliaris as well as in Canis litpus and Canis valpes. No other 

 author, to our knowledge, has noticed its presence in the Carnivora. 

 Unfortunatel_y, we only came across Gruber's paper after our 

 animals, with seven exceptions, were dissected, though we feel 

 confident that if the muscle had been at all well developed it 

 would not have escaped our notice. The seven animals which 

 we specially examined without tijiding the slightest trace of a 

 peroneo-tibialis were Cryptoprocta (14), Cynictis (31), Herpestes 

 griseus (30), Canis aureus (50 a), Canis mesomelas (51), Nasna 

 narica (an extra specimen), and CercoIe2^tes (72). We also pro- 

 cured an additional specimen of Canis familiaris and made an 

 extremely careful examination of the posterior tibial region. We 

 are confident that there were no muscular fibres deep to the 

 popliteus passing between the tibia and fibula and corresponding to 

 the rotator fibulae so well known in the Lemuroidea. Lower down 

 in the leg, however, we came across a few verj^ delicate strips of 

 muscle passing transversely from one bone to the other and with the 

 greatest difficulty separable from the origin of the flexor fibularis. 

 The nerve-supply of these seemed to be from the anterior tibial. 

 We fear that the question of the presence of this muscle through- 

 out the Carnivora must remain for future investigation. 



Fliwor hrcvis dirjitoriivi. — This muscle is in most cases a direct 

 continuation of the plantaris after the latter has passed round the 

 back of the tuber calcis. It usually has a fleshy belly in the sole, 

 which divides into four slips ; these soon become tendinous and 

 form the flexores perforati for the four outer toes. Just before 

 the deep tendons pass though them a fibrous ring is given ofi: 

 which surrounds the deep tefidons. Each slip of the flexor brevis, 

 after having beeu perforated, unites and divides again to be 

 inserted into the middle phalanx. In some cases muscular slips 

 are given off in the sole from the conjoined deep tendons to those 

 of the flexor brevis : these have already been noticed in Hymia 

 striata as displaced lumbricales. The Hysenidas and Canidae are 

 remarkable for the absence of muscular fibres in the flexor brevis, 

 which is therefore a mere expanded, fibrous continuation of the 

 plantaris tendon. This arrangement was noticed in Bycena 

 striata (33, 35), Proteles (32), Canis familiaris (39, 40), Canis 

 aureus (50, 50 a), Canis mesornelas (51), and Canis layopus (53). 

 In Byana crocuta (37) there was not only no fleshy belly to the 

 flexor brevis, but that muscle was not continuous with the 

 plantaris, which ended iu the tuber calcis. Kelley (XXIV.) 

 noticed that in Ursus maritimus (55) the flexor brevis was oidy 

 fleshy for the 2nd and 3rd toes, the tendons for the 4th and 

 5th being continuous with the plantaris. In Ursus americanus 

 (59) the flexor brevis rose entirely from the calcaneum, 

 though iu the other Bears (55, 57, 58, 62) the usual arrangement 

 existed. In one specimen of Viverra (17), Macalister fouud no 

 tendon to the outermost toe. 



