Roy L. Moodie 455 
epiphyses in the two groups cannot be used as a criterion of relationship 
since neither has these structures. It might be more logically claimed 
that they are related because of the absence of epiphyses. But the 
presence or absence of these elements, it seems to me, is of little value. 
If it is of value, then the lizards and mammals are related, for epiphyses 
are abundantly present in both groups. That epiphyses are not good 
diagnostic characters for the distinction of large groups of vertebrates is 
well shown by the fact that they occur in the lizards and that here they 
may be abundantly present or almost entirely absent. They may be a 
good generic or family character, but this point requires further investi- 
gation. Some lizards (Chameleon, Heloderma, Amblyrhynchus) have a 
great number of epiphyses, some (Phrynosoma, Eremias) have but few. 
Draco, apparently, has none. 
I find no epiphyses in the crocodiles. I have examined young specimens 
of the Alligator mississippensis Daudin, five inches in length from the tip 
of the snout to the base of the tail, and have seen no indications of any 
epiphysial growth. I have also examined adult skeletons of the garial, 
the Florida crocodile, and the Mississippi alligator, but have seen nothing 
articular cartilage on the ends of the limb bones. 
The lizards offer an interesting field for more extended investigation on 
this subject. Hpiphyses occur abundantly in some forms and principally 
at both ends of the limb bones, on some of the girdle bones, on some of 
the carpals and tarsals, on both ends of the metacarpals and metatarsals, 
at the proximal end of the phalanges, on the spines of the vertebrae, and 
Dollo has reported them on the skull and ribs in certain forms, although 
I have not been able to find them on any of the skulls at my disposal, 
except that epiphysial structures are present on the posterior end of the 
mandibles of Amblyrhynchus. 
The epiphyses of the lizards are not always bony. Some are merely 
calcified cartilage while a few are true bone, as Parsons has shown in 
Iguana. I have made sections of the epiphysial regions of Amblyrhynchus 
and have definitely ascertained that there are Haversian canals and 
lacunae present in the epiphyses. The fact that some of the epiphyses are 
not bone is, however, a matter of but shght importance. The important 
fact is that there are distinct structures present in the lizards which 
correspond with the similarly placed epiphysial structures in the 
mammals. 
The lizards examined are the same as I have listed in a previous 
contribution on the lizard sacrum and the reader is referred to that 
