474 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vor. 48 
15. Distance from anterior margin of foramen magnum to the 
VOMEDINE, MOtCh) mw. 4 clam eee eres ceria e oa ae Cee ene 118 
16. Distance from vomerine notch to posterior margin of the 
bony? palates 4... c's ao eter th oe ee ee eee 99 
30. Greatest width between the outer margins of the orbits.... 21¢ 
Tscherski relies primarily upon the three cranial indexes elabo- 
rated by Nehring and himself for the expression of racial char- 
acteristics of the horses. They may be explained briefly as follows: 
(1) The Frontal Index (Stirnindex, Tscherski; Index 1, Nehring) 
expresses the proportional relation of the length of the skull to its 
width. It is obtained by dividing the basicranial length (dimension 
1 of the above table) by the greatest width of the cranium at the 
orbits (dimension 30) and multiplying by 100. Skulls with a 
frontal index less than 227 are regarded as brachycephalic (breit- 
stirnig, Tscherski), those with an index between 227 and 240 
mesocephalic (mittelstirnig), and those above 24 dolichocephalic 
(schmalstirnig ). 
(2) The Orbital Index (Augenindex, Tscherski; Index 111, 
Nehring) expresses the relation of the length of the facial part to 
the cerebral part of the skull by dividing dimension 4 by dimension 
3 and multiplying by 100. The greater the resulting figure, the 
more long-faced is the horse and vice versa. This index is less 
reliable than the next which is intended to express the same relation, 
but it is utilized because only by it Nehring’s numerous measure- 
ments become available for comparison, as his tables do not include 
dimension 5. Skulls with an index less than 190 may be regarded 
as short-snouted, with more than 190 as long-snouted. 
(3) The Facial Index (Facialindex, Tscherski, p. 278) expresses 
the length of the snout by reducing the distance between orbit and 
tip of snout (dimension 5) to a percentage of the basicranial length. 
Tscherski does not state where he draws the line between short- 
snouted and long-snouted horses, but 65 or 65.5 probably expresses 
his idea (see p. 278). 
These indexes in the Lofoten skull may be tabulated as follows: 
Frontale index Aoncaice sacred oe Soa ene ee eee, 
Orbital’ indexes. 552 Rah Bee ae, einen Mes 
Pacral “index ee) ol SOR et 2 6 oe ee clos ee 
It will be seen, consequently, that this west Norwegian pony 
belongs to Tscherski’s “ small”? horses (having a basicranial length 
of less than 460 mm.) ; that it is exceedingly brachycephalic ; and 
that both according to the orbital and the facial indexes it is short- 
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