498 M. F. Sumichrast on the Habits of some Mexican Reptiles. 



family Varanidse, inhabits exclusively the hot zone which extends 

 from the western slope of the Cordilleras to the shores of the 

 Pacific : it has never been met with, to my knowledge, on the 

 side of the Gulf of Mexico. Its conditions of existence confine 

 it to hot and dry locahties, such as the districts of Jamiltepec, 

 Juchitan, and Tehuantepec. 



The observation of the habits of the Heloderma is the more 

 difficult, as this animal, from the sedentary mode of Ufe imposed 

 upon it by its semi-nocturnal habits, eludes continuous investi- 

 gation. Moreover the extreme terror which it inspires in the 

 natives has contributed not a little to leave its history in obscu- 

 rity. The gait of this reptile is exceedingly slow and clumsy, 

 which is explained by the shortness and relative thickness of its 

 limbs, as also by the want of flexibility in the articulations. In 

 very old individuals, or in the females before oviposition, the 

 belly acquires a great lateral development, and drags upon the 

 ground — a deformity which adds still further to the repulsive 

 aspect of this curious creature. 



It is usually in holes of greater or less depth, dug at the roots 

 of trees or under a mass of vegetable debris, that the Heloderma 

 takes up its abode. Here it remains, during the greater part of 

 the day, rolled up in a state of almost complete immobility. It 

 rarely issues from this state of torpor, except early in the morn- 

 ing, before day, or in the evening, at the times when the terri- 

 colous insects are creeping upon the pathways in the woods. 

 As might be expected from the constraint and slowness of its 

 movements, the Heloderma can only attack an easy prey. Its 

 food consists essentially of apterous insects, earth-worms, Myria- 

 pods, and small species of Batrachia, and sometimes even of 

 putrefying animal matters. It is fond of the eggs of Iguanas ; 

 and it is not unusual to meet with it roaming about near the 

 holes dug in the sand, in which these eggs have been left to the 

 action of the rays of the sun. 



The Heloderma is a terrestrial animal in the full acceptation 

 of the term, and its organization is in intimate relation with its 

 mode of life. Its round and heavy tail could not in any way 

 serve it as an instrument of natation, and its short, thick toes 

 could not enable it to climb trees. Hence it is not in the im- 

 mediate vicinity of rivers or in the depths of the thick forests 

 that this reptile must be sought, but rather in dry spots on 

 the margins of the woods, or in old clearings, the soil of which 

 is covered with vegetable debris, with rotten trunks and grasses. 

 Without having any positive evidence upon this point, I am 

 much inclined to think that this Saurian remains for a longer or 

 shorter time in a sort of cestival lethargy, analogous to that which 

 has been observed in the Alligators in some districts of America. 



