340 Dr. C. W. Andrews — Expedition to the Fayum, Egypt. 



whole of the outer half of p.m. 4 are broken away ; the portions 

 missing are left unshaded in the figure. 



The crowns of the brachydont molars are quadrate in outline ; 

 their outer wall is formed by a W-shaped ectoloph composed of the 

 following elements : — a large and prominent parastyle (p.) and 

 mesostyle (ms.) and a less-marked metastyle {mt.) united by V-shaped 

 paracone {"pa.) and metacone (me.). On the posterior face of both 

 the parastyle and mesostyle is a small but well-defined tubercle, 

 marked x in the figure ; these tubercles seem to belong to the 

 cingulum. The inner half of the tooth is composed of two tubercles, 

 the protocone {fr.) and hypocone (h.), which give a V-shaped 

 pattern in wear, and the anterior arms of the V's, which are the 

 longer and may include traces of the protoconule and metaconule 

 respectively, run outwards tovi^ards the parastyle and mesostyle. In 

 the last molar only there is a small hypostyle (%.). M. 2 and m. 1 

 are similar to m. 3, except for the absence of the hypostyle and their 

 smaller size. 



ft'' ; fW 



m^ nj^ m' pm'^ prm pm^ tim' c 



— .t>- I- 



Fig. 1. — Upper dentition of Jic^a/oAyrft.?; eoc««.«s, gen. et sp. nov. The premaxillary 

 region with the incisor (i.), shown by dotted lines, is provisionally restored 

 from a premaxilla referred to in a former paper as possibly that of Phiomia. 

 One-third nat. size. 



Fig. 2. — Front of upper jaw of Saghatherium antiquum, And. & Bead., showing 

 enlarged incisor. One -half nat. size. 



c. canine; h. h}'pocone; hy. hypostyle; i. first incisor; i.^, third incisor; 

 «w.^"^, molars ; me. metacone; ots. mesostyle ; mt. metastyle; ^^. parastyle ; 

 pa. paracone; p.m.^-"^, ]3remolars ; pr. protocone. 



In the fourth premolar the outer half of the tooth is broken away, 

 but the inner portion is well preserved. This tooth differs from the 

 first molar in the much smaller size of the hypocone (using the 

 same nomenclature as for the molars), which is reduced to a small 

 cusp situated on the extreme postero-intei'nal border of the tooth. 

 In p.m. 3 the hypocone is still smaller, and in p.m. 2 it is entirely 

 absent. P.m. 1 is relatively more elongated than p.m. 2, the proto- 

 cone is smaller, and there is a small postero-internal cusp on the 

 cingulum which may represent the hypocone. In the premolars 

 the ectoloph seems to consist of the parastyle, the paracone, and 

 the metacone only ; but in the posterior premolars there is a small 

 qusp on the cingulum which may represent the mesostyle. 



The canine is an elongated two-rooted tooth immediately in front 

 of the anterior premolar and in the same line. Its crown consists 



