BBY DAVIDSON BLACK 
occipital or pontine surface to the highest point over the vermis 
the measurement is 70 mm. From the frontal to the occipital 
pole of the cerebrum the maximum length is 120 mm. The 
greatest diameter between the floccular areas of the cerebellum 
is 57 mm. 
Brain stem, cerebellum and basis cranii. In a ventral view 
(figs. 1 and 17), the relation of the large sessile olfactory bulb 
(B.O.) to the tractus olfactorius (Tr.O.), is well shown. Between 
the diverging lateral and mesial olfactory tracts, which in the 
recent state occupy special bony grooves, a small prominence 
represents a depressed area in the skull floor for the lodgment 
ABBREVIATIONS 
' R. ant. ectosylv., ramus anterior ecto- 
sylvii 
R. desc. ss., descending ramus of the 
sulcus suprasylvii 
R. post. ectosylv., 
ectosylvii 
Ar.Floc., floccular area 
Ar.Lat., lateral area of interfloccular 
mass 
Ar.Pyr., pyriform area 
B.O., protuberance corresponding to 
fossa for lodgment of bulbus ol- 
ramus posterior 
factorius R. post. ss., posterior ramus of the sul- 
For. Condyl., protuberance correspond- cus suprasylvii 
ing to condylar foramen S. ans., sulcus ansatus 
For. Lac., irregularities marking site S. arc., arcuate constellation 
of foramen lacerum basis cranii S. cor., coronal sulcus 
M.A.I., elevation indicating position  S. diag., diagonal sulcus 
of internal auditory meatus S. ent. lat., entolateral sulcus 
Md. V., protuberance corresponding to _ S. lat., lateral sulcus. 
foramen ovale transmitting the  S. obl., oblique sulcus (of Holl) 
mandibular division of the trigeminal 8S. presylv., presylvian sulcus 
nerve 
Mz. V., protuberance which appar- 
ently corresponds to the foramen 
rotundum for the passage of the 
maxillary division of the trigeminal 
Oph. V., protuberance corresponding 
to foramen lacerum orbitale 
Oph. & Mx. V., protuberance corre- 
sponding to skull groove lodging 
the first two divisions of the trigemi- 
nal nerve in their passage to a com- 
mon exit at the foramen lacerum 
orbitale 
Post. Rh. Fiss., posterior rhinal fissure 
S. Ps., pseudosylvian fossa—processus 
acuminis 
S. suprasylv., suprasylvian sulcus 
S. trirad. post., triradiata posterior of 
Kappers 
T.O., elevation corresponding to fossa 
lodging tuberculum olfactorium 
Tr.O., ridge indicating skull groove 
for lodgment of the tractus olfactor- 
ius 
Vermis, median area of interfloccular 
mass 
IT., tubercle corresponding to the 
position of the optic foramen 
