164 



THE EXTINCT liATKACHIA, RE1TILIA 



The humeri are short, with stout, head and condyles, slender shaft, and considerable curvature. Head presented 

 inwards and upwards; condyles downwards, the outer angle most prominent. A slight tuberosity on inferior aspect 

 near inner angle. Outer outline of shaft quite concave. Deltoid ridge a prominent crest, its posterior margin falling 

 considerably short of the head; the outer margin continuous, convex. Postero-inferior crest broken; the planes of the 

 two make a little more than a right angle with each other. 



M. 

 .01)7 

 .035 

 .02 

 .009 



Total length humerus, (straight) 

 Diameter condyles. 



" deltoid crest to middle shaft, 

 " shaft at middle (transverse), 

 Nothing but a fragment of the great trochanter with head, is left of the femur. 

 the latter, straight; with Bat outer side, and narrow. Form quite as in Propleura. 



This individual appears to be mature. Its remains are accompanied by a lew fragments of a large individual, of . 

 this species or T. sulcatus. 



Position. The upper green sand bed of the Upper Cretaceous of New Jersey. Discovered by John Haines. 



The former is continuous with 



TAPHROSPHYS SULCATUS, Leidy. 



Tab. 



Platemys sulcatus, Leidy. Proceed. Acad. Nat. Sciences, Phila., 1886, 808. Cretaceous Reptiles, 108. 

 XIX, lig. I. 



Pubis attached to a narrow, little elevated longitudinal sutural surface. Margins of sternum thin, Hat; surface 

 deeply recticulate grooved: bones, especially the marginal, thin, light, eostais thinned at margins; mesosternum longer 

 than wide. 



This species is so fragile as to he rarely preserved in more than a few pieces. The largest part of a single indi- 

 vidual that has come under my notice, consists of the more or less complete posterior three costal hones of the cara- 



pace, with last vertebral marginal, some anterior costals, xiphisternum, etc. Another similar series of fragments of 

 another individual was procured at the same time and place, i. (,., near Barnesboro, N. .1. 



These specimens show that the last pair of costals is not separated by a vertebral bone, and the penultimate 



pair is only separated at their anterior ptjrt. This last vertebral is of reduced and rounded proportions; the one pre- 

 ceding it is of the normal form, i. e., with elongate postero-lateral border. The costal capitula are developed on all the 



bones. Sutural surfaces are present on the inferior face of the proximal and contiguous pairs of costal hones, for the 



attachment of rudimental and inferiorly placed vertebral pieces. One elongate extends from the last true vertebral 

 over the anterior margin of the last pair of costals. The latter have two scars; the anterior rectangular, the posterior 

 ovate. The pygal hone is elongate ovale anteriorly; inferiorly if presents a, Battened longitudinal ridge, and an ele- 

 vation on the anterior part of the lateral margin. 



The last costal has a very irregular inferior surface. Its proximal part is thickened, and then rises outwardly 

 into the ridge, that margins the iliac pit. This ridge is most elevated on the capifulum, and develops an acute pro- 

 cess outwards from it. The posterior part of the pit is occupied by an ovoid hone, truncate outwardly where it articu- 

 lates with the ilium, which appears to he a, radimental costal element belonging to the second rudimental vertebra] 



piece. If presents a, rudimental capifulum towards the hitler. 



Behind this piece a narrow transverse groove extends outwardly, and is bounded by a longer groove anteriorly 

 and a, short one posteriorly. Near the distal extremity of the bone is a thickening, which terminates abruptly round 

 an ovate posterior margin, [ts anterior margin is on the posterior edge of the preceding costal hone. The distal 

 margin scuds a, short process downwards. 



The penultimate is characterized by the high crest a, little in front of its posterior margin, proximally, which 

 encloses in front the iliac pit. The crest continues distally, and turning abruptly encloses the extremity of the pit. 



The external margin of the last costal is strongly a.ngula.fe; the penultimate less so. As in all of our Pleurodira, 

 the marginal sutures are half squamosal, and with strfiform ridges. 



Tin; externa] sculpture is coarsely reticulate, lending to enclose areas longitudinal with the costals towards their 



middle and distal portions. That of the marginal hones is closer. The derma] scuta are separated by sutures indis- 

 tinctly marked on the carapace in all the species of our Pleurodira. In this species flic vertebrals are very broad. 



