No. 1605. ON THREE SPECIES OF SHA-TURTLES—HA Y. 195 
the median ones. The frontal scute is about as long as the fronto- 
parietal; the latter is not so long as are the parietals. In C. caretta 
the fronto-parietal is long, and the parietals very short. Chelonia 
olivacea Eschscholtz has been, by some authors, referred to the genus 
Lepidochelys. The type of the species was found in Manila Bay and 
it possessed six pairs of costal scutes. If this number of costals shall 
be found to be constant it may serve to establish the genus mentioned. 
Possibly when the carapace of Caretta remivaga shall have been 
secured it will be found to have a like number of costal scutes. Baur 
places this skull in the genus Lepzdochelys,; but it does not conform 
to his definition of the genus, inasmuch as the frontals enter the orbits 
and the descending processes of the prefrontals connect with the - 
palatines. 
The following measurements and percentages are given in order 
that comparisons may be made with the skulls of Caretta caretta 
and Colpochelys kempi, whose dimensions and percentages are given 
on page 190. 
Table of measurements. 
eee | Percent- 
Dimen- 
—-| 
age of 
Parts measured. sions. | cranial 
| axis. 
mm. | 
SrOutaroroceipitaleon diy) cheese ee ae ee eee eee 144 | 100 | 
Width from outside to outside of quadrates__-----_----__-__--_______.- | 117 | 81 
SmoOutscovendlomsSuprTrao cei plLal hy ROCESS wee eee nn en | 187 129 
SNOW HO GoxRSOAY Ol SCMIEMTNOSON eee 176 122 
Front of tympanic cavity to extremity of squamosal________________. 43 30 
Snout to line joining hinder borders of articulations for lower jaw-_-_ 125 87 
en athvOrOnbi tees ease eae ie ee ws We one oa Se ees 58 40 
JE EA TE OR Oye Ovi he se ae ee ee 45 31 
CMiriincelee Or nNASAalll lOGMOW? O10 Oli ee 23 16 
interop“ icalyspaCenees =e ae wees ae ee ae eee ees Cae ee eee ak ee st 45 31 
Height of roof of skull above articulations for lower jaw __-_-__---_- 100: 69 
Front of prefrontals above cutting-edge of maxilla__________________. 52 36 
Least width of combined pteryeoidss 222 2-2-8 25 17 
ID ISERIES) OIE CMO MS [OSTATIC | SHON ONG Se , 47 32 
WHiGhin OF Gaosmnell @nemnbas lo@lubae ———— 37 26 
Distance between hinder ends of maxillz_________________-_________ 95. 66 
LGM GAN Oi Wey Ort WOMIEP WOW ers ee SSE 122 85 
From tip of lower jaw to coronoid process-_-_-__------------------------ 82 57 
IFES CHRO SID iy S 1G eet ee ee ene ne ee ae ee 82 OP) || 
Breadth of hinder end of ramus of lower jaw_-_----------------------- 26 18 
From tip of lower jaw to mental foramen_______---_-_-_-_-________--. 56 39 
Thickness of ramus below coronoid process-_-_----------------------__-_| 16 ; 11 
\ Sehex | 
From the foregoing measurements it will be seen that the end of 
the supraoccipital process and the extremity of the squamosal extend 
a considerably less distance behind the occipital condyle than they do 
in Caretta caretta. The slope of the skull (Plate X, fig. 1) from rear 
to front is about as in the Atlantic loggerhead, but it is less convex. 
The pterygoids are narrower behind the ectopterygoid processes. The 
choanee are placed farther forward and they are much wider behind. 
The rami of the lower jaw are shorter and likewise their symphysis. 
The hinder end of the ramus, measured across the articulation for the 
@ Amer. Naturalist, XXIV, 1890, p. 487. 
