408 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



other genus except Romcrolagus. The foot-Hke extremity of the 

 zygomatic process of the squamosal is short, about as it is in Lcpits, 

 but the posterior free extremity of the malar is long. 



The audital bullae and the external auditory meatus are typical 

 for the family as detailed in the general account ( page 346 ) . 



The fenestration of the maxillse is reduced to a small degree, 

 being about as it is in the genera Pronolagiis and Romcrolagus. 



The mandible of LiinnoJagus has a very large, rounded, angular 

 process, similar to the form in Syk'ilogiis, but the ascending ramus 

 is relatively wider. 



Teeth (pi. xci, 4; figure 44, 4). — The first upper incisor in Liinno- 

 lagus has a shallow, simple groove in front, filled with cement. The 

 first upper molariform tooth has the three usual reentrant angles, a 

 deeper median one and two lateral shallower ones. The first lower 

 molariform tooth, divided into an anterior and a posterior portion by 

 a single deep reentrant angle from the external face, presents on its 

 anterior face two deep crenated reentrant angles and one or two 

 smaller ones, and a broad crenated reentrant angle on the anterior 

 half of the external surface. The whole anterior half of the tooth 

 is rather solid looking, and more quadrilateral in outline than is 

 usually the case with this tooth in other genera. The second, third, 

 fourth, and fifth upper molariform teeth have each a deep, internal 

 reentrant angle, extending- about three-quarters the distance across 

 the tooth as in Lcpiis, Orycfolagus, and Sylz'ilagiis, but unlike them 

 the internal fourth of the reentrant angle is rather wide, that is, its 

 adjacent edges are not in contact for that fourth. The second, 

 third, and fourth lower molariform teeth have each the lateral 

 diameter of the posterior half of the tooth equal to about four-fifths 

 the lateral diameter of the anterior portion. The last upper molar is 

 small, elliptical in section. The last lower molar is also small, con- 

 sisting of anterior and posterior portions which are more nearly 

 subequal in size than they are in most of the genera. The anterior 

 part is the larger and more elliptical, the posterior smaller and more 

 rotund in outline. 



Vertebral Column. — The cervical vertebras (pi. xcii, 4) of Liinno- 

 lagns have nothing to distinguish them from the same vertebrae of 

 several other genera, being noticeably different only from the two 

 extremes, Lcpiis with elongated cervicals, and Pronolagiis with 

 more shortened ones. The individual vertebrae are uniformly short- 

 ened, the costal processes project relatively far from the sides of the 

 centrum, the anterior and posterior spines of these processes are less 

 prominent than they are in Lcpus. The true transverse process i.«^ 



