72 FLORIDA GEOLOGICAL SURVEY-EIGHTH ANNUAL REPORT. 
The gutter for the neck is more deeply excavated than in either 
of the two shells mentioned and several others examined. Of the 
free border of each epiplastral the anterior two-thirds is much 
more obtuse than in the specimens of P. floridana. As in the lat¬ 
ter, the horn-covered area on the upper surface of these bones is 
very narrow, being only 7 mm. wide at the epi-hyoplastral su¬ 
ture and only 4 mm. at the midline in front. 
In the collection, with the number 7099, is a left xiphiplastral 
bone which is referred provisionally to this sub-species (pi. 5, fig. 
7). The length along the median suture is 68 mm.; the width 
along the hypo-xiphiplastral suture is 61 mm. The corresponding 
measurements of the two mentioned shells of P. floridana do not 
differ much. The greatest thickness at the hypo-xiphiplastral su¬ 
ture and about 20 mm. from the free border is 11 mm. As in the 
case of P. floridana, the width of the horn-covered area on the up¬ 
per surface and at the front of the bone is 8 mm. The depth of 
the notch at the outer end of the femoronanal sulcus is much 
greater than in P. floridana, but it may be that this is not normal. 
A right third costal plate, No. 7100, is shown on plate 5 (fig. 8). 
Its width at the outer end is 48 mm. It appears to agree in all 
respects with the corresponding bone of the shells of P. floridana 
at hand. 
CHELYDRA LATICARINATA, NEW SPECIES. 
Plate 6, figs. 6-7. 
Type-specimen. —The sixth left peripheral. No. 7094 of the 
Florida Geological Survey. 
Type-locality and formation. —Vero, St. Lucie County, Flor¬ 
ida. Pleistocene. 
Diagnosis. —Peripheral bones considerably thicker than those 
of C. serpentina; those over the bridges with a sharp keel ; upper 
surfaces smooth. 
Among the chelonian bones collected at Vero are ten which 
appear to have belonged to the genus Chelydra. Three of the 
bones are parts of oostals, five are peripherals, one a neural, and 
one is the inner portion of the left hyoplastral. A study of these 
bones makes it evident that two species are represented. As the 
type of the one above named a bone, No. 7094, the sixth left 
peripheral (pi. 6, fig. 6) is taken. 
This bone has a length of 42 mm. It indicates that the length 
of the carapace was close toi 315 mm. about 12 inches; therefore, 
