100 PROCEEDINGS OF THE NATIONAL MUSEUM vol.73 



part of the external malleolus, over another groove upon the lateral 

 calcaneum, to the plantar surface over the peroneal groove of the 

 cuboid, and to an insertion upon the ventro-latero-proximal part of 

 the first metatarsal. In the Phoca the tendon passed over a groove 

 just craniad of the external malleolus, through the deep groove upon 

 the lateral calcaneum, and then to the plantar surface through the 

 peroneal groove of the cuboid, here so deep that it formed a bony 

 tunnel arched over by a process of the cuboid in contact with meta- 

 tarsal 5. There was also a groove for this tendon upon the first 

 tarsale and insertion was normal upon the base of metatarsus 1. 

 Miller considered that some of the fibers of this muscle took origin 

 also from the tibia and fibula. 



M. peroneus brevis (figs. 13, 25, 26). For a description of this 

 muscle in the Zaiophus, see the next. In the Phoca it was practically 

 hidden by the peroneus digiti quinti. It arose from the proximal 

 half of the cranio-lateral shaft of the fibula. Its tendon was in con- 

 tact with that of the digiti quinti to distad of the calcaneum, at 

 which point it diverged to insert upon the process directed ventrad 

 upon the base of metatarsus 5. This has been reported as a separate 

 muscle in the remainder of the eared seals that have been dissected, 

 in Arctocephahis and Etimetopias arising deep to the digiti quinti 

 and inserting upon the fifth metatarsal. 



M. peroneus digiti quinti (figs. 13, 25, 26) in the Zalophus certainly 

 occurred fused with the brevis division. This arose from the lateral 

 head of the fibula and from half the lateral border of the shaft, from 

 the peroneal ligament and from the deep aponeurosis of the soleus. 

 The tendon passed over the lateral malleolus just caudad of the 

 peroneus longus tendon, then beneath the latter, and over the pero- 

 neal groove upon the calcaneum, splitting into two branches, one 

 going to the proximal termination of the first phalanx of digit 5 

 and the other to the metatarsal of the same digit. In the Phoca 

 it arose by aponeurosis from the cranio-lateral head of the fibula. Its 

 very slender tendon passed over the deep fibular groove directly 

 caudad of the lateral malleolus, as in Zalophits. It then stretched 

 distad along the lateral side of digit 5 as a well-defined tendon only 

 as far as the basal phalanx. Miller said that in Arctocephaliis it 

 arose below the soleus, but this does not conform to his description 

 of the latter muscle. 



In Odohenus Murie found a peroneous quartus, and what he con- 

 sidered as the homologue of a peroneus tertius, the interpretation of 

 the latter especially being doubtful, as it arose from the calcaneum. 

 Its tendon joined that of the quartus division, and both therefore 

 extended to the fourth metatarsal. 



As with the manus, the short muscles of the pes are here omitted, 

 the full account by Murie and Muller being deemed entirely adequate. 



