CROCODILIANS, LIZARD8, AND SNAKES. 481 



Uoulenjier ' further adds the iollowing differences between the two: 



lu the //. sitspectiim tlie oral i)ortion of the preniaxillarj is narrower, and its 

 asceudiiig iuteriiarial bar wider tlian in ihe If. liorridiwi. Eight or nine x)remaxil- 

 lary teeth are present in H. horridiim and only six in H. suspecttim. Dr. Shufeldt, 

 liowev(!r, represents eight teeth in the latter species, but his figure showing all the 

 teeth as of the same si/.e looks very diagrammatic. The postorbital arch is more 

 slender in U. suspecium. Palatine and pterygoid teeth appear to be constantly 

 absent in H. suspectum, whereas they are present in both slvulls of H. horridnm 

 examined by me, as well as in those described by Trosehel and by Kaup 



1 remark on these statements, that in two crania of //. .sunpeetum 

 before me there are no pterygoid or palatine teeth, except that in one 

 there are two rudiments on the palatine of one side and one rudiment on 

 the other. In both there are alveoli for eight premaxillary teeth, and 

 in both only one of these is unoccupied by a tooth. In both the pre- 

 maxillary spine is wide at the base, as described by Boulenger for 

 the H. suspectum, but in both it is long, as described by him for the 

 H. horridum. 



Ilahifs. — It has been shown that the bite of the Helodcrma suspecium 

 is, under favorable circumstances, poisonous. P^xperiments tried at or 

 near Tucson, Arizona, by Dr. Irwin, United States Army, in 1862-G3, 

 did not demonstrate this fact, as fowls bitten by the Heloilerma did not 

 die. Dr. K. W. Shufeldt was bitten by a specimen at the Smithsonian 

 Institution, Washington, and he describes his symptoms in a paper 

 published in the American Naturalist. 



The results were not serious nor diflerent from such as result from 

 any lacerated wound. Experiments made by Drs. S. Weir Mitchell and 

 Edward F. Eeichert, of the University of Pennsylvania, showed that 

 the saliva injected into the body is speedily fatal to pigeons and fowls. 



The history of observations as to the venomous characteristics of 

 this species is thus given by Dr. II. W. Shufeldt:- 



At the present writing the wide variance of opinion in these premises is truly 

 remarkable, for some of our most distinguished investigators still disagree in the 

 matter, and those, too, who have made the most exhaustive examinations of the 

 saliva of this reptile. 



As long ago as 1857, .John Edward Gray, of the British Museum, in referring to 

 Necturus, said, "I know of no other instance of a batrachiau having this structure 

 of its teeth, nor do I know of any instance, except in the Mexican li/ard called 

 Hcloderina horridum, in which all the teeth are uniformly furnished with a basal 

 cavity and foramen, and this lizard is said to be noxious; but tlie fact has not been 

 distinctly proved." 



Prof. E. I). Cope, who first clearly characterized this reptile ami gave it its pres- 

 ent name of Ilelodenna suspectum, has stated that "though the lizards of this genus 

 could not be ])roved to indict a poisonous bite, yet the salivary glaiuls of the lower 

 jaw were emptied by an etfereut duct which issued at the base of each tooth, and in 

 such a way tliat the saliva would bo couveyed into the wound by the deep groove 

 of the crown." 



Then several j'ears passed before much else was published upon this special topic 



iProc. Zool. Soc. Loud , 1891, p. 110. 

 -New York Medical Journal, May, 1891. 



NAT MUS 98 31 



