Mylodon harlani, from Rock Creek, Texas. 347 



the California mount. In all there are in the Texas collection 

 five cervicals, one of which lacks the neural arch, while in 

 another the centrum bears but one pedicel. Of the dorsals, 

 approximately thirteen are present, represented by two prac- 

 tically complete vertebrae, one with half the arch preserved, six 

 centra, and eight neural arches, not all of which could have 

 belonged together. The one complete pelvis includes at least 

 ten coossified sacral vertebrae, while the number of caudals 



Fig. 4. Sixth cervical vertebra of Mylodon harlani, from Bock Creek, 

 Texas. One-fourth nat. size, a, anterior aspect ;p, posterior aspect ; az, pre- 

 zygapophysis ; nc, neural canal ; pz, postzygapophysis ; vc, vertebrarterial 

 canal. 



Fig. 5. Seventh cervical vertebra of Mylodon harlani. 

 size, rf, rib facet ; other lettering as in fig. 4. 



One-fourth nat. 



present is six and a half, all from the proximal portion of the 

 tail. 



Cervicals. — If one may judge from their color and general 

 appearance, at least two, possibly three, animals are represented 

 by the five cervicals which have been preserved. One of these, 

 which may be regarded as the sixth, as it articulated fairly well 

 with a typical seventh, has the following characteristics : The 

 centrum presents a more or less pentagonal anterior face, while 

 the posterior one is six-sided. The anterior face is distinctly 

 convex, with a slight depression in the center, the posterior 

 face being concave, with a well-marked convexity around the 

 periphery. Dorsally two good-sized nutritive apertures are 

 seen flanked by two much smaller ones, while ventrally there 

 is a distinct keel-like prominence on the anterior half which 

 broadens and flattens posteriorly to give the hexagonal outline 

 to the hinder face of the centrum. The neural arch arises on 

 two massive pedicels situated over the anterior two-thirds of 

 the centrum on either side so as to give ample space for the 



