The " Plathander'' (Xenopus laevis). 
343 
Internal Anatomy. 
The alimentary canal and its glands are similar to the same organs in 
the frog except that the liver, besides the right and left lobes, has a dorsal, 
transversely elongated lobe on the right side and a minute spherical 
fragment on the left side. 
The lungs are much more highly developed than in the frog. In cross- 
section it shows a structure quite reptilian ; in fact, it shows higher 
development than that of the koggelmannetje (Agama atra). There is a 
distinct longitudinal, central bronchus with numerous radial branches. 
f- 
FiG 1. — The left half of the pectoral gkdle, neutral view. Pc = clavicle (membrane 
bone) ; PcC = pre-coracoid cartilage ; C =^ coracoid ; Cc = coracoid cartilage ; M = 
metasternum ; Sc = scapula ; A = glenoid cavity. 
Skeleton. — With regard to the appendicular skeleton, the claws of the 
first three toes need mention ; they represent the differentiated skin 
covering the terminal phalanges of the toes concerned. 
Gadow contradicts the statement (which he says is occasionally made) 
that the pectoral girdle of the Aglossa is arciferous. For Xenopus, how- 
ever, much could be said in favour of such a statement. Eeference to the 
Fig. 1, which is not very diagrammatic although it may appear to be so, 
shows that the epicoracoid cartilages certainly forms an arch. Also there 
is an overlapping of epicoracoidal cartilage although this overlapping is 
not of the same sort as in typical arciferous girdles. The body of the 
metasternum (M) is ventral to the body of the coracoid cartilage (Cc), 
