On thk status uf CHKLONFA DEPRESSA, GarnKni 



l?v Dknk ]\. Fi;v, .liiiiior Assistant. 



(IMjiti's xix-xxii., ami Fi^s. 88-49.) 



The I'eceiit species of marine turtles represent tlie few 

 surviving foi-nis of a once flourishinp- o-j-oup, wliicli reached its 

 zenitli probahlv in late Mesozoic times. There no lonufer exist 

 such giy-antic and diversified monsters as Airholon, rrdtonti'ijK. 

 and Mioliiiii((, but. such a uniformity of structure prevails that 

 only four allied genera are admitted. It is natural that 

 three of these, which occasionally visit the European coasts, 

 should have been known to Linnspus, but it is sui'pi-ising that 

 the remaining' two, i'ltl pochcl ijx /.c/j//*//, Garnian, and I 'lii'lmu'ii 

 d('pre/ii<ii, (Jai'man, should have remained unknown to iiaturalists 

 till comparatively recently, showing that even now we cannot 

 safely consider our knowledge of the marine turtles as 

 complete. 



Fig. 38. — Map showing the areas from which the various marine turtles have been 

 recorded. The true tiabitats are rather more reritricted. The thickly dotted area 

 shows the distribution of C/ie/oiiia vivil 'S, Caretta caretUi, and Kiflmoclu-lys 

 iinhricata. The sp-ir.;ely dotted region = Cheloiiia fafioiiica, Care/la olivacea, and 

 Eietmochelys squamosa. Horizontal stria ^^ Co//>oche!vs kt'>ii/>ii. Perpendicular 

 stri-B = Clit^loiiia drpirssa. Oblique stria = Caretta reinivaoia. (a supposed species 

 needing confirmation). 



Of the tive^ marine turtles, the Green, Hawksbill, and 

 Loggerhead are almost cosmopolitan in habitat, the other two 

 being peculiarly restricted (fig. 38). Cnlporlieltis kfnipii is 

 recoi'ded only from the Gnlf of ]\fexico and as far north as 



I A sixth species of turtle lias been described by Dr. Hay (Proc. 

 U.S. Nat. Mus., xxxiv., 1908, p. 194, pi. x., fig. 1-3, pi. xi., fig. 5) as 

 Caretta renilriKja, from the <iulf of Tehuantepec, Western Coast of 

 Mexico. It is fomided on two skulls, one of which was earlier referred 

 by Dr. Baur (Amer. Nat., xxiv., 1809, p. 487) to Lepidochelys olivacea, 

 Esch., and it certainly needs confirmation. 



