R. Lydekker — On Foml Mammalia. 65 



recent skull. The only loss wliicli it lias sustained is a portion of 

 the right zj^gomatic arch ; part ot the posterior border of the left 

 orbit ; the right outer incisor and canine ; and the left inner incisor 

 and the first premolar. The cheek-teeth belong to the permanent 

 series, and are but slightly worn. The extreme length of the upper 

 surface of the skull is 0-081, which is practically the same as in the 

 type of C. laticurvatnm (0-0815), although some specimens of the 

 latter (var. metopias) are larger. The present specimen differs, how- 

 ever, from that species by the pi'esence of a distinct diastema; which 

 is situated between the canine and P^- 1 , instead of between the 

 earlier premolars,' as in the so-called /'lesiomeryx. In this respect, 

 therefore, the skull under consideration differs from the first seven 

 species named above. It differs, moreover, in another very important 

 point. In C. laticAirvatum (which as already said is the only species 

 which agrees in size with the present specimen), the nasals are long, 

 narrow, convex bones, wider in front than behind, terminating 

 anteriorly in a notch, and having a depression at their junction with 

 the frontals. In the present specimen the nasals are very short, quite 

 flat, and the two together form an oval, terminating anteriorly in an 

 acute point. There is no de[)ression in the frontal at the junction of 

 these bones, neither are the frontal sulci as conspicuous as in C. 

 laticurvatum. In all the other species of which the cranium is 

 known, the nasals are long and terminate anteriorly in a notch. 

 C. elongatiim (in which there is no diastema) and C. cadiircense agree 

 with the present specimen in having indistinct frontal sulci, and no 

 depression at the root of the nasals. The present specimen agrees with 

 the much smaller last-named species, and G. commune, in having the 

 anterior border of the posterior nares situated on the line dividing m^- 1 

 and "1- ^- The figures of the crania of the above-mentioned species do 

 not show the other cranial sutures. In the present specimen the 

 premaxillse extend upwards to articulate with the frontals. The 

 lachrymal has a small facial, and a large orbital portion. The facial 

 ■vacuity is narrow and long. The frontal portion of the cranium is . 

 flat ; the sagittal crest well developed ; and the profile much less 

 arcuated than in C. laticurvatum. The squamosals extend high up on 

 the temporal foss83 ; and the auditory buUse are of very large size. 

 There is a minute inner cusp to pm. 2 , which seems wanting in other 

 forms : the inner cusp of pm. 3 is rather larger than in C. laticnrva- 

 tnm, and apparently comes near to Moiiillactherium. There is no 

 diastema between any of the premolars, and the hind lobe of ^- 3 has 

 three cusps. 



The second specimen (Fig. 2) is a good deal crushed and broken, 

 but is very important in having the mandible attached to it. This 

 cranium has nasals similar to the last, a diastema between the canine 

 and pm- i , and may, therefore, be referred to the same species as the last ; 

 its somewhat smaller size indicates that it probably belonged to a 

 female. The lower dental series shows a diastema occurring between 

 pm. 1 and pmrs ; as is usually the case in the species Nos. 5 and 6 



1 It is assumed that in C. gracile the diastema has the same position as in C. 

 cadiircense. 



DECADE III. — VOL. 11. — NO. II. 6 



