REMARKABLE TORTOISE, TESTtJDO LOVERIDGII, 509 



one of them is distinguishable without a lens. In pulling up the 

 carapace, quite half of these plates sepai-ated easily from the 

 vertebrae and adhered to the carapace, or rather to the dermis, 

 which shows that they are not completely fused with the vertebrae 

 at this stage. 



The costals are slightly more developed, and are disposed as 

 follows : — The vertebral and costal epidermal shields meet each 

 other in a zigzag suture which has seven angles. At each of 

 these, three shields meet corner to corner. It is beneath these 

 points that the centres of the incipient costal plates are located. 

 They are therefore alterna.tely nearer to, and further from, the 

 vertebne. Those nearer to them tend to develop proximally, and 

 are more or less rhomboidal in shape, and those further away 

 develop distally down the rib, and are more triangular, the apex 

 pointing towards the marginal region. 



The first, second, and third are not quite in contact with each 

 other, the third, fourth, and fifth are nearly in corner to corner 



Text-figure 17. 



Carapace of newly-hatched j'oung, from without (nat. size). 

 Epidermal shield-sutures ; vertebrae and ribs ::::;::. 



contact, the fifth and sixth are joined by oblique suture as in the 

 adult, forming an oblique bony bridge beneath the shield-suture. 

 The seventh and eighth are but commencing their formation. 



The pygals are absent altogether. 



The marginal plates are not recognizable as such at this stage, 

 but minute groups of bone-granules are detectable beneath the 

 shield-sutures between marginals three to eight. Posteriorly 

 they are not visible, although their primary particles may be 

 present in the dermis. 



At about 60 mm. the eight pairs of ribs (2nd to 9th) are still 

 distinct and of normal length, but are modified, the proximal 

 5 mm. having become very slender, and the remainder flattened 

 and adherent to the dermal costal plates where these are present. 

 In the particular specimen figured a ninth pair of ribs are fully 

 developed, and reach the mai-ginals on both sides. 



At this stage {vide t3xb-fig. 18) the development of the 



