168 



THE EXTINCT BATRACHIA, REPTILIA 



ridge-like and other elevations between them. On some portions of the surfaoe they assume a longitudinal direction. 

 A portion of the margin is rather abrupt and thick. Thickness of bone, one inch from margin less than nearer the 

 same; greatest thickness, lines. 



APPENDIX TO THE TESTUDINATA. 



Lembonax, Cope. 



Established on the remains of a marine turtle which presents the peculiarity of a regu- 

 lar continuous inner margin of the hyo- and hyposternal bones, without radiating processes 

 for intercalation with that of the opposite side, or emargination for the median lontancllc. 

 It follows either that there is no fontanclle, or that the fontanelle is continuous to the 

 xiphisternal, in either case differing from Chelone and Puppigerus. The hyo-xiphistrr- 

 nal suture is transverse, as in Emydidse, for a portion of its length nearest the; median line; 

 or this element having transverse parallel sutural outlines may be intercalated between 

 hyo- and hyposternals, as in Pleurosternum, though this I consider altogether improbable. 

 The suture for the cpisternals oblique, and not squamosal, as in Chelone and Chelydra, 

 hiit by shallow gomphosis; the anterior inner margin of the hyosternal retreating outwards 

 a little, and leaving space apparently for mesostcrnum: the hyo-hyposternal suture by 

 fine deep gomphosis ; the hyo-xiphisternal by shallow coarse gomphosis. 



The common neck of the sea pulo-procoracoid bone is short, and more like an Emydoid 

 than a Chelonioid. 



On the whole, there is reason to suspect that this form is more nearly related to Che- 

 lydra than to Chelone. 



Lembonax polemicus, Cope. 



Spec. nov. 



The sternum presents a longitudinal angle on eaeh side, learing the median plane portion of the sternal bones 

 rather narrow, as in species of Chelone. The angle is slight, the surface rounded. The inner faoe of Hie hyosternal 

 is strongly radiate-ridged towards the inner anterior angle, and the inner face of the margin serate; the posterior por- 

 tions of the margins are slightly roughened. The inner margin of the hyposternal is regular, smooth, and thinned ob- 

 tusely; it is without radiating ridges. 



The external surface is smooth, without sculpture. 



The sternum has been small for the size Of Hie animal, judging by Indications furnished by the scapular glenoid 

 cavity. No portions of the carapace arc preserved. 



Antero-posterior length hyosternal, 



Width do. to longitudinal angle, 

 Antero-posterior extent hyposternal, 

 Width do. to angle, 

 Long diameter extremity scapulo-procoracoid, 



Do. neck of do., 



Do. distal extremity scapula, 



M. M. 



.24 



. I ::<; 



.1525 



. 155 



.115 



.098 



.059 



This species was derived from Hie Eocene marl of New Jersey, where excavated by the Farmingdale and Squankum 

 Marl Company, to the Director of which. A. .1. Smith, I am Indebted for the specimens on which the present, identifi- 

 cation is based. 



