Marsh — New Reptiles from the Laramie Formation. 453 



Claosaurus annecte?is ) sp. nov. 



The reptiles of the Laramie allied to Hadrosaurus are 

 numerous and highly specialized. One of the forms most 

 distinct, but not abundant, is here described, and the type 

 specimen is a nearly complete skull and skeleton. This will 

 be fully described by the writer, but as the pelvis presents 

 some points of interest it is represented in figure 4 below. 

 The ilium exhibits no special characters of importance, and 

 agrees in the main with the corresponding bone of the type 

 of the genus. The ischium is especially elongated, and very 

 straight. The pubis is represented by a very large, expanded 

 prepubis, and a mere remnant of the postpubis, as is well 

 shown in the figure. 



Figure 4. — Pelvis of Claosaurus annectens, Marsh. One sixteenth natural size. 

 a, acetabulum ; il, ilium ; is, ischium ; p, pubis ; p', postpubis. 



This important specimen is from the Laramie of Wyoming. 



The fossils described in the present article were all collected 

 by Mr. J. B. Hatcher, whose discoveries in the Rocky 

 Mountain region are well known to paleontologists. 



New Haven, Conn., April 18, 1892. 



