84 GEOLOGICAL SURVEY OF TEXAS. 



Austin couiit3', in Southern Texas.* It is described under the head of 

 PUauchenia spatula^ antea, and is figured on Phite XXI, Figures 3, 4. 

 Mr. Cuuiniins did not obtain it in Northwest Texas. 



HOLOMENISCUS SULCATUS, Cope. 



Sp. nov. Plate XXIII, Figure 4. 



Tliis large lama is represented by a mandibular ramus, from which the 

 condyle, coronoid process, angle and symphysis are wanting. The molar 

 teeth are all preserved. The length of the sei-ies of the latter is about 

 the same as in the H. hesternus, but the forms of the teeth are different. 

 The ramus is also much deeper in proportion to the other measurements. 

 The first premolar presents a grinding face of an elongate triangular 

 form, with the apex anterior and a little incurved. The true molars in- 

 crease rapidly posteriorly, the anteroposterior diameter of the first being 

 less than half that of the third. The inner wall of the true molar is not 

 Hat as in the II. hesternus, but it is divided by an open groove opposite 

 the deeper internal groove, as in the species of PUauchenia, thus dis- 

 tinctly marking off the anterior from the second column. In addition to 

 this there is an anterior and a posterior marginal internal rib on the second 

 molar, and an anterior marginal rib on the third. These do not exist in 

 the H. hesternus, but are present in the PUauchenia spatula and the camel. 

 The camel possesses a keel on the internal side of the crown in the posi- 

 tion of the groove in the H. sulcatus. 



Owing to the loss of the anterior part of tlie ramus, the character of the 

 canine tooth can not be ascertained. The first true molar is crowded by 

 the adjacent teeth, so that its internal wall overlaps the latter by a little. 

 This is probably an individual peculiarity. 



The following comparative measurements show the relations of this 

 species with the H. hesternus: 



* Mr. J. B. Walker makes the following note on the locality and occurrence 

 of this fossil : 



" The locality should be Bowie Bend, Austin county. The fossil was found 

 by my assistant, Mr. B. S. Brown. * * * The bluff is in two terraces, and 

 tlic bones, when in place were in tlie upper part of the lower terrace, mixed 

 with the snmll siliceous pebbles, which are in moderate quantity at one locality 

 only, and this is where the river has made the greatest excavation, or in the 

 bend proper." 



It may be of interest in this connection to note the fact that this is the same 

 locality from which the fossils were obtained which were described by Dr. W. 

 M. Carpenter in American Journal of Science in 184G, p. 244, E. T. D, 



