Cope.] 490 [Sept. 17, 
Size medium ; fourth upper premolor equilateral ; all cusps acute ; true 
molars. 0165. 2 i sweas wsasadsinwxe ee eae aparagaisie te le'8ie .. ML. subtrigonus. 
aaa. Cusps of last premolars compressed in lower jaw. 
Least. Second and third lower true molars subequal; cusps, especially 
the internal, elevated ; anterior inner confluent into an edge; true 
molars, .013....... al cvetiete <'aisre sep prowess SCRE oe ee H. angustus. 
Largest ; cusps of inferior molars obtuse; P-m. III .008, its heel short 
aM SMAllsis.svicaccoweee vs Sire eRe Oe Sas eeceeeeee lL. mandibularis. 
Medium ; last inferior molar larger than penultimate ; true molars, .014; 
Petis. LUE 00 Ghee scianisieienie aig ew wisisisiere aieie-oce,0 ... Antsonchus sectorius. 
Of M. turgidus there are two specimens ; and of IL subtrigonus, UM. an- 
gustus and WM. mandibularis one each. 
In the W& turgidus there are no cingula on the fourth premolar. It is 
wider than long, and the external face is a little flattened. The tubercles 
are conic; the external has a small one at the anterior base, and a rudi- 
ment at the posterior base, and there is a low one on the posterior side at 
the middle. The second true molar is wider than the first. The tubercles 
are all round in section. Besides those already mentioned, there is a rudi- 
ment of a posterior inner on the first, which is represented by a cingulum 
on the second. The latter has basal cingula all around except on the inner 
side ; the same are visible on the first true molar in a rudimental condition. 
Enamel nearly smooth. 
The inferior molars are of robust proportions. Their sizes are, commenc- 
ing with the largest: P-m. IV; M.I1; M.I; M. III. The last molar is 
only half as large as the penultimate. It has two anterior and an external 
Jateral tubercles, and a heel. On the penultimate molar, there are two an- 
terior tubercles with a trace of anterior inner ; also a broad flat heel, with 
a low tubercle on the external side. The constitution of the first true mo- 
lar is identical. The fourth premolar has a rudimental heel consisting of 
a low tubercle only. The principal cusp is conic and is over the middle 
of the transverse diameter, and a little behind the middle of the antero- 
posterior diameter. No cingula. Enamel nearly smooth. 
Measurements. M. 
Maxillary bone. 
Length of base of P-m. IV, M. land M. IT............ .0175 
¢ anteroposterior. ......... -0055 
Diameters base P-m. IV ; tYADSVETSC... cc eu cece .0065 
x anteroposterior.......... -0060 
Thameters base NET ; transverse...........0.. .0070 
é 5 anteroposterior ......... .0060 
Diameters base M. IT ¢ transverse. .........000- -0095 
Mandible. 
Length of bases of last four molars.........eeeeee+0-- «0250 
§ anteroposterior ......... .0070 
Daamsetets Ems LV transverse....... sarerosten 20055 
