266 ZAGLOSSUS. 
a common insertion at the mastoid region just dorsal to the external ear and 
posterior to the insertion of the sternomastoid. 
Beneath the splenius, and covering the back of the neck is the biventer 
cervicis, a broad muscular sheet, arising from the spines of the first thoracic and 
all the cervical vertebrae. It inserts by tendinous fibers along the dorsal part 
of the occiput corresponding to the lambdoid ridges. 
The rectus capitis posterior minor is quite as large as the preceding and arises 
from the anterior margin of the atlas, dorsal to the transverse process. Accord- 
ing to Fewkes, its origin in the Echidna is from the posterior rim of the atlas. 
In both it passes forward as a thin sheet to insert upon the posterior part of 
the occiput, somewhat ventral to the insertion of the biventer cervicis. 
The rectus capitis posterior major was not identified, although it is said to 
be present in the Echidna as a very small muscle from the anterior extremity 
of the spinous process of the axis to the occiput. 
The obliquus inferior originates from the lateral surface of the spine of the 
axis and passes forward as a strong muscle to insert into the dorsal part of the 
lateral process of the atlas. 
The obliquus capitis superior is a short thick muscle, from the ventral side 
of the transverse process of the atlas to the occiput. 
The rectus capitis lateralis lies just ventral to the last, and arises from the 
anterior face of the lateral process of the axis. It passes forward as a stout 
round muscle to insert just lateral to the insertion of the obliquus superior. 
Mivart states that in the Echidna this muscle has the usual relations, 7. e., from 
the atlas to the occiput, but in the Proechidna its origin is certainly fromthe axis. 
The longus capitis arises from the ventral side of the transverse processes of 
the sixth and seventh cervical and first dorsal vertebrae. It passes forward 
along the side of the neck as a ribbon-like band, that becomes a flat tendon 
at the region of the axis and inserts into the jugular process of the skull, just 
posterior to the tympanic bone. 
The scalenus is similar to that of the Echidna, arising from the transverse 
process of the second to seventh cervical, and inserting on the first rib. 
CauDAL MuscLES. — The dorsal muscles of the tail are so intimately con- 
nected that they are with difficulty separated into distinct bundles. 
The portion corresponding to the extensor caudae medialis is of muscle fibers 
from the spines and dorsal surfaces of the last two lumbar and the succeeding 
vertebrae, and from the medial edge of the ilium; from this muscle mass, tendons 
pass to the articulating processes of the vertebrae. 
