688 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XL 



regarded as a continuation of the main axis than the other. 

 The forking is in the horizontal plane. Hemidactylus glea- 

 dovii. * 

 (o) Condition bifid. — A structure entirely of the nature of a repro- 

 duced tail, becoming bifid at some distance from its com~ 

 mencement, arises from the extremity of a broken normal tail. 

 There is no reliable indication that one branch should be re- 

 garded as a continuation of the main axis more than the other, 

 (i) The forking is in the vertical plane. Mabula 



carinata, specimen B. Lygosoma telfairii.^ 

 (ii) The forking is in the horizontal plane. Mabuia 

 carinata, specimen A. 



(d) Condition trifid. — A structure of the nature of a reproduced 



tail continues the axis of the normal tail from a point 

 where the extremity of the latter has been broken off 

 between two vertebrae. The last vertebra before the break 

 is permanently bent, and from its convex side arises a struc- 

 ture of the nature of a reproduced tail. This structure soon 

 becomes bifid. Both forkings are in the horizontal plane. 

 Calotes cristatellus. 

 [This case possesses features of both (a) and (c).] 



(e) Condition trifid. — The main axis of a broken normal tail is 



continued by a structure of the nature of a reproduced tail. 



At its commencement this gives off two symmetrical 



branches which are without the typical endo-skeleton of a 



reproduced tail. The forkings are in the horizontal plane. 



Anolis grahami. 



("In the absence of information regarding the internal structure of 



the supernumerary tails of the Tupinambis described by Quelch, it is 



uncertain whether the case should be placed under (a) or (<?).] 



The above arrangement is adopted merely for the purpose of discrim- 

 inating between the main characters of the cases which have been 

 described, and it is not suggested that such extensive sub-division rests 

 on differences between the physiological factors which brought about 

 these abnormal appearances. Indeed, if it be true that accidental injury 

 is a frequent or universal cause of supplementary caudal growths, it is 



* f Jour. Bombay Nat. Hist. Soc, loc. cit. 



