172 



RECOEDS OF THE AUSTRALIAN MUSEUM. 



Fig. 42- — Chfhuia depressa, Garm. Carapace of 

 specimen No. 7. 



In the type specimen (No. 6) tlie sliields are ratlier soft but 

 distinctly horny, and exhibit distinct concentrically an-antred 

 tortoise-shell markings. In the five younger ones they are 

 covered by the strongly |iitted areolse to such an extent as to 

 prevent a satisfactory examination of this character. In the 

 laro-est one however (No. 7), in which the areolae have pi-e- 

 sumablv been shed, the boundaries are marked by vei'y tine 

 furrows, while the}' are quite soft, almost flesliy to the touch, 

 and not at all horny. 



The carapace tlieii, differs markedly from ('. iin/ilas in the 

 following points: — Instead of being tectiform in transverse 

 section, owing to the reiiexed marginals it presents the curves 

 of a bow. It is also more depressed in the median line. The 

 outline is an ahnt)st even broad oval, but slightly longer than 

 broad, with a much deeper nuchal bay. The nuchal shield is 

 sometimes divided. The nnii-ginais are strongly retlexed except 

 in very young specimens whose rotundity is no doubt ilue to 

 their i-ecent accommodation within tlu' egg. Areola^ are 

 present in very young examples. 



