316 Al,EXANDER G. Rl'THVEN, 



deep water lagoons and lakes. It prefers the shores that are wooded 

 and is seldom seen where tliese Iiave been cleared. Its favorite 

 habitat is the bushes overhanging the water, but it always remains 

 near the ground or the water, that is, it does not climb to the higher 

 branches of the trees. When alarmed it throws itself from the 

 bushes and dashes away through the shallow water, seeking refuge 

 ah^ng the bank. Where the stream or lagoon is narrow it may cross 

 it. and twice I observed frighteued individuals rush across a deep 

 stream ten to fifteen meters wide. 



When rimning through the bushes or slowly in an open area 

 locomotion is on all four legs, but when moving rapidly through open 

 Spaces and always Avhen running through the water the body is 

 raised upon the bind legs, and the tail is slightly up curved and 

 held in the air. This method of locomotion is a very advantageous 

 one for a lizard occupying the habitat that Basüiscus does. From 

 the bushes over-hanging the water retreat from land animals can 

 only be had by swimming or running through the mud and shallow 

 water along shore. We flushed scores of individuals and never saw 

 one swim; always they jumped from the bushes and dashed away 

 through the water on their bind legs. In this conuection it is 

 interesting to note that the bind legs are very strongly developed 

 and that it is these limbs alone that bear the dermal lobes and the 

 small webs between the tirst and second digits. These may be con- 

 sidered as adaptations to riparion conditions. The strong bind limbs 

 are capable of carrying the body for a considerable time, and the 

 dermal lobes and webs keep the animal from sinking in the soft 

 mud and fiinction as paddles when the feet do not touch bottom. 

 In the ones observed to cross deep water the bind feet were moved 

 exactl}^ as on the land, and so rapidly that the body could not sink 

 i. e., the animal literally ran through the water on its bind legs. 

 This dilfers from Sumichkast's ^) account that "in swimming, he 

 raises the head and breast; bis fore feet strike the water as oars. 

 whilst bis long tail furrows it like a rudder", We could not deter- 

 mine whether or not the fore feet were used when in deep water. 

 but it was quite evident that they were relied upon but little if at 

 all, the bind limbs being the principal organs of locomotion, and it 

 was not apparent that the tail functioned in any degree as a rudder. 

 The Statement of Gabb, as quoted by Cope-). that the animal runs 



1) 1. c, p. 505. 



2) in: Journ. Acad. nat. Sc. Philadelphia, 1875, p. 125. 



