114 PROCEEDINGS OF THE NATIONAL MUSEUM voT.S^ 



cene types occurring at Hagerman, As to "whether this line led to 

 any of the large species of LepU'S there is no certaint5^ As yet no 

 types have been described from the Pliocene or Pleistocene of North 

 America clearly bridging the seemingly trivial, yet apparently per- 

 sistent, dental characters cited by Dice as distinguishing Hypolagus 

 from Lepus and SylvUagus. Moreover, it is interesting to note that 

 fossil materials recognized as including both Hypolagus and Lepvs 

 have been found in an early Pleistocene occurrence at Anita, Ariz.^ 



HYPOLAGUS LIMNETUS. new species 

 FiGUEES 2, 3 



Type. — Skull, right ramus of mandible, and atlas, TJ.S.N.M. no. 

 12619. 



Locality. — T. 7 S., H. 13 E., about 2 miles south of the Plesippus 

 quarry, near Hagerman, Idaho. 



Horizon. — Hagerman lake beds. 



Specific characters. — Size near that of Sylvilagus nuttalli grangen^ 

 much smaller than Hypolagus vetus. Rostrum relatively short and 

 cranial portion elongate. Cranium shallower posteriorly and less 

 depressed with respect to the rostrum than in S. nuttalli grangeH. 

 Posterior nasal opening dorsoventrally deep and transversely con- 

 stricted. Bullae very large. Basi-occipital narrow and elongate. 

 Teeth about equal in size to those of &. nuttalli grangeri. Anterior 

 upper incisors strongly recurved with anterior groove more nearly 

 median in position. P- with two unequal reentrant folds and P3 with 

 anterior external reentrant fold relatively deep. 



Material. — The skull (fig. 2) belonging to the type is remarkably 

 well preserved and includes the entire dentition. However, the speci- 

 men lacks the nasals, parietals, the left and part of the right zygoma, 

 and the right bulla. The atlas and greater portion of the right ramus 

 of the mandible were found in position with the skull, the ramus 

 incomplete only in the region of the angle. In addition to the type a 

 few isolated teeth and some fragments of limb bones are recognized 

 as belonging to this species. 



Description. — In size Hypolagus limnetus is only slightly smaller 

 than the sage cottontail {Sylvilagus nuttalli grangeri) now living 

 on the Snake River Plains, although considerably larger than the 

 pigmy rabbit {Brachylagus idalioensis) . Compared with the sage 

 cottontail the fossil skull has a relatively shorter rostrum and an 

 anteroposteriorly longer basicranial region. The cranial portion of 

 the skull is not so depressed posteriorly, and the supra-occipital is dis- 



" nay, O. P., Proc. U. S. Nat. Mus., vol. 59. pp. 628-631, 1921 ; see also Dice. L. R,. 

 Papers Michisau Acad. Sci., Arts, and Letters, vol. IG, pp. 379-382. figs. 8-11. 1932. 



