Case.] Turtles. 375 



strong ridge runs far inward toward the brain-case, and receives 

 the distal end of the pterygoid bone. Below the opening of the 

 stapedial notch, the posterior margin of the bone is swollen and 

 rugose. The petrosal is somewhat distorted ; it is elongate, 

 and joins the supraoccipital, opisthotic and pterygoids inter- 

 nally, and the quadrate by a strong sutural area externally. 

 Between the proximal extremity of the petrosal and the ptery- 

 goid is a large oval foramen. Just proximate to the junction 

 with the quadrate there is a strong, rugose area for attach- 

 ment of the masseter. The lower surface of the skull is seen in 

 plate lxxix. 



The mandible has a flat alveolar surface, with the outer border 

 scarcely raised above the surface. There is no beak, and the 

 symphysis is quite short. The specimen described is incom- 

 plete, terminating at the posterior end of the dentary bone. 

 The jaw at this point is very low ; much lower, proportionally, 

 than in T. serrifer. The inner surface of the dentary is marked 

 by a shallow groove. Plate lxxxi, figures 4, 5. 



The head of T. latiremis as a whole is broad behind, becom- 

 ing gradually narrower anteriorly, to about the hind termination 

 of the maxilla?, where the jaws rapidly approach each other to 

 form a rather blunt point, which is completed by the premaxil- 

 laries. The skull is somewhat flattened from above downward, 

 giving a general appearance of that of Thalassochelys. 



The scapula has the form characteristic of the sea turtles. 

 The neck is comparatively long, and supported by a rather thick 

 extremity, which bore two articular faces. One, the upper, 

 or rather the outer, is supported on a prominent ridge arising 

 from the base of the scapular portion ; it is triangular in out- 

 line, and afforded attachment to the proximal end of the cora- 

 coid. The second face is the scapular face of the glenoid cavity ; 

 it is somewhat oval in outline, and joins the coracoid face at a 

 little less than a right angle. The margin's are thickened and 

 rugose. Behind the expanded portion of the bone bearing these 

 two faces the neck is much contracted, and then expands rap- 

 idly to form the body of the bone, from which spring the scapula 

 proper and the proscapular process. These were slender and 



