500 M.F. Sumichrast on the Habits of some Mexican Reptiles. 
movement persists for a long time after death in this reptile ; 
and if we may believe the relations of the Indians, it is prolonged 
for forty-eight hours or more in the head after its separation 
from the body. 
The colour of the spots scattered over the body and limbs of 
Heloderma horridum is subject to variations, due to age or to 
difference of locality. These spots pass from whitish yellow to 
reddish brown, through a series of intermediate shades ; their 
arrangement, which is far from constant, cannot furnish precise 
descriptive characters. Age likewise produces great changes in 
the size: some individuals attain a length of nearly 5 feet. 
II. Family Iguanide. 
Genus Ievana, Laur. 
Iguana rhinolopha, Wiegm. 
‘Ieuana verde’ of the Creoles. _‘ Guchachi-guéla’* of the 
Zapotec Indians. 
Genus Cyciura, Harlan. 
Cyclura acanthura, Wiegm. 
‘Ieuana negra’ of the Creoles. ‘ Guchachi-chévé’ * of the 
Zapotec Indians. 
Although the two species of Jguanide of which the above is 
the synonymy belong to different genera, I have thought it 
best to combime the facts which I have collected upon their his- 
tory in a single article, in order to give prominence to the prin- 
cipal points in their organization and habits which have induced 
the separation of the genera Iguana and Cyclura. 
Representatives of these two genera of reptiles are found over 
a great part of the territory of the Mexican republic—that is to 
say, in all that zone which stretches along the shores of the two 
oceans, and is known under the name of the Tverras calientes. 
The true Iguanas are more diffused than the Cyclwre upon the 
eastern side—a circumstance which is easily explained by the 
fact that this part of the country, being furrowed with water- 
courses and small lakes (/agunas) and covered with a luxuriant 
vegetation, presents biological conditions the most favourable to 
the animals, which prefer the vicinity of water. The Pacific 
coast, on the contrary, is dry and sandy—a condition which 
suits well with the more terrestrial habits of the Cyclure, and 
favours their multiplication. 
* These native names are literal translations of the Spanish terms 
Iguana verde and I. negra. The Zapotec name of the Iguana is Guchachi; 
guéla means green, and chévé, black. 
