718 



REPORT OF NATIONAL MUSEUM, 1902. 



The gTocTi turtle is easily distinguished from the other Porto -Rican 

 marine turtles Ijy the single pair of elongated prefrontal shields on 

 top of the snout. The shell alone can be recognized by having only 

 four costal shields and by the shields not overlapping- posteriorly. 

 The loggerhead {Caretta carettdt) has live costal shields, while the 

 hawksbill {Eretrnochelys inihrleata) has overlapping shields (tig. 193). 



None of our expeditions to Porto Rico brought back an}^ specimens 

 of the green turtle, but its occurrence in the waters surrounding the 



Fig. liW. — Kr?;tmochelys imbricata. i natural size. Blu'll from above. No. 25045, TT. S.N. M. 



island is well known. Dr. 15. W. Evermann, in his general report on 

 the investigations in Porto Rico of the United States Fish Commis- 

 sion steamer FisJi llawl' in 1899, writes that it is rare except at the 

 east end of the island, and he accounts for the scarcity of turtles by 

 the absence of largo areas of shallow water with sandy bottom. 



Genus ERETMOCHELYS " Fitzinger. 



1828. ('arrf/ft KiTC4EN, Nova Acta Acad. C;«s. Leop., XIV, p. 270 (type, Chelonia 



imbricata; not of Rafinesque, 1814). 

 1843. Eretmocheli/s YiTzi^GEU, Syst. Kept., p. 30 (same type). 

 1873. Onychochelys Gray, Proc. Zool. See. London, 1873, p. 397 (type, 0. kraussi). 



c^spsT/iov, oar; j^Ai;?, turtle. 



