I 914 ] Taylor: Aquatic Adaptation in the Carnivora 475 



Lutra canadensis 



30 Hind limb not specialized for 



use as a paddle. 



31 Head of femur with pit for 



lig amentum teres. 



32 Tibia and fibula long and 



light. 



33 Pes not expanded. 



34 Metatarsals and phalanges 



not noticeably elongated 

 or flattened. 



33 Fifth digit not the longest. 



36 Hind limb not markedly back- 

 ward extending. 



Latax lutris nereis 



30 Hind limb specialized for use 



as a paddle. 



31 Head of femur without pit for 



ligamentum teres. 



32 Tibia and fibula comparative- 



ly heavy. 



33 Pes expanded. 



34 Metatarsals and phalanges 



noticeably elongated and 

 flattened. 



35 Fifth digit the longest. 



36 Hind limb markedly backward- 



extending. 



CHARACTERS APPARENTLY NOT RELATED TO AQUATIC 

 ADAPTATION 



Lutra canadensis 



1 Infraorbital foramen large but 



not so elongate as in 

 Latax. 



2 Zygomatic process of frontal 



prominent. 



3 Angular process represented 



by a hook and internal shelf. 



4 Zygomatic arches fairly wide- 



spreading. 



5 Coronoid process rounded and 



bent forward. 



6 Incisive foramen oval. 



7 A large condylar vacuity pres- 



ent 3.17 mm. from foramen 

 lacerum posterius. 



8 Spine of fifth thoracic verte- 



bra platelike, rounded pos- 

 teriorly; ending in knob. 



9 Suprascapular border of sca- 



pula having a dip in the 

 curve. 



10 Deltoid ridge of humerus 



somewhat expanded, in- 

 definite. 



11 Entepieondylar foramen bound- 



ed by light bar; elongate. 



Latax lutris nereis 



1 Infraorbital foramen large 



and elongate. 



2 Zygomatic process of frontal 



less prominent. 



3 Angular process indicated by 



tubercle. 



4 Zygomatic arches not so wide- 



spreading. 



5 Coronoid process rounded and 



bent backward. 



6 Incisive foramen more nearly 



round. 



7 A minute foramen present 



near condyle 7.3 mm. from 

 foramen lacerum posterius. 



8 Spine of fifth thoracic verte- 



bra thicker, straight, not 

 rounded posteriorly; not 

 ending in knob. 

 Suprascapular border of scap- 

 ula having an even curve, 

 no dip. 



10 Deltoid ridge of humerus a 



definite single ridge. 



11 Entepieondylar foramen bound- 



ed by heavy bar; small. 



Prom these tables it develops that 36 characters, or 69.6 per 

 cent, are apparently related to aquatic adaptation, while 11 char- 

 acters, or 30.4 per cent, are apparently not so related. Although 



