ON A SPECIMEN OF EEMIDACTYLUS GLEAD0VI1. 33 



bearing on the above is furnished by a specimen of Lygosoma telfairii 

 (Scincida) in the Cambridge Museum, in which the tail is bifid in its 

 distal portion. Though it has not been dissected, there is little doubt 

 that the bifid portion is a new growth. Seen from the dorsal surface, 

 the longer (left) branch of the tail is continued in the long axis of the 

 body,. and bears the short (right) branch as a lateral outgrowth. The 

 normal tail of this species is covered ventrally by broad transverse 

 scutes, and elsewhere by small scales. In this abnormal example the 

 row of ventral scutes leaves the median ventral line of the tail and 

 passes gradually on to the right side and consequently towards the 

 short branch of the extremity. At the bifurcation the broad scutes 

 cease, the whole of the bifid portion being covered by small and quite 

 regular scales. The dorsal scales of the stump, on the other hand, 

 become lateral on the left-hand side as they approach the bifurcation, 

 and there become continuous with the rows of scales on the left side 

 of the long (left) branch of the extremity. Hence, so far as the 

 epidermis is concerned, the left side of the longer branch of the new 

 growth represents the dorsal surface of the animal, while the right side 

 of the shorter branch represents the ventral surface. It is noteworthy 

 that in this instance, as in that of Hemidactylus, there is a departure 

 from the normal condition in the undivided portion of the tail, which 

 is not a renewed structure. 



It is probable that duplicity of the renewed tail is not very un- 

 common among certain genera of lizards, and I have lately received 

 a specimen of Anolis grahami (Iguanidce) with a renewed tail which 

 bears two symmetrically developed dwarf tails on its sides, so that 

 the new growth has a trifid appearance. It is desirable that all such 

 cases should receive careful examination, as the matter has a direct 

 bearing on the problem of symmetrical growth. 



List of Figures. 



Plate A, Fig. 1.— Hemidactylus gleadovii, ventral surface, nat. size Xlf. 

 j} 2. — Do. do. do. of tail, nat. size X 3. 



„ B „ 3. — Transverse section through proximal portion of tail. 

 )f 4 # — Do. do, short branch of tail. 



„ 5. — Do. do. long branch of tail. 



,, „ „ 6.— Longitudinal section through bifurcation of tail. Nat. 

 size x 10. 

 P. Proximal portion. L. Long branch. S. Short branch. 

 N.B. — Figures 3 to 6 are somewhat diagrammatic. The shrunken condition 

 of the spinal cord and connective tissue cores is no doubt a result of the pre- 

 paration for section cutting. In life they would fill the lumens of the neural 

 canal and cartilage tubes respectively. 

 5 



