490 



BULLETIN 58, UNITED ST.\TES NATIONAL MUSEUM. 



S78 



entire top of head smooth; body rather depressed, the depth being 

 l>nt slightly more than half the width of the carapace; carapace with 

 377 three keels, a median, contin- 



uous, broad, prominent, and 

 one on each side consisting of 

 four narrow, low keels, one 

 on each costal, in a discon- 

 tinuous series inasmuch as 

 being placed oblicjuely across 

 the costal shields the poste- 

 rior end of each keel extends 

 externally beyond the ante- 

 rior end of the one follow- 

 ing; nuchal broader than 

 long ; first vertebral squarish, 

 somewhat broader in front 

 than behind; all vertebrals 

 broader than long, about as 

 broad as the adjacent costals; 

 margin slightly turned up, 

 not serrated behind, though 

 the posterior corner of each 

 marginal extends slightly 

 beyond the one following; 

 eighth and ninth marginals 

 broadest ; plastron flat, emar- 

 ginate beliind sharply bent 

 at the bridge, truncate ante- 

 riorly ; posterior lobe as long 

 as the width of the bridge, 

 narrower than the shell ; ab- 

 dominal seam longest, equal- 

 ing gular and humeral seams 

 together, the latter being the 

 shortest; pectoral seam as 

 much longer than the femoral 

 seam as the latter is longer 

 than the anal seam ; inguinal 

 shield twice as large as axil- 

 lary ; toes webbed to the tips ; 

 tail long, a little more than 

 one-half the length of the 

 carapace, tapering to a point. 

 Color (in alcohol): Carapace raw umber, each shield with a large, 

 polygonal, excentric, well-defined reddish brown spot; each marginal 



FlGS.377-378.—0cADI.V SINENSIS. NAT. SIZE. 377, CARA 



pace; 37S, PLASTRON. No. 19, Sci. Coll. Tokyo. 



