LATERAL MUSCLE IN TELEOSTEI. 331 
characteristic conical structure, however, considerably further 
forward than does the mesio-ventral portion. The latter contains 
fibres which are directed from below anteriorly to above posteriorly 
on the lower parts of the flanks ; but, as noticed above, the fibres 
of the ventral surface change in direction the nearer they 
approach to the mid-ventral line so as to be disposed parallel to 
the long axis of the body. I have failed in every instance to 
find a septum, such as is described by Knauer, dividing the 
mesio-ventral portion into two superimposed layers. 
It has been stated above that a strand of the mesio-ventral 
portion is prolonged anteriorly to be inserted on the hypo-hyal. 
This strand, together with the hyo-cleithrafe *, constitutes the 
neck musculature. Knauer (5) recognised these parts of the neck 
musculature, and adds the following note (op. cit. p. 11):— 
“Die Angabe Schneiders, dass sich der Sternohyoideus * aus 
zwei der Linge nach zusammengewachsenen Muskeln (Hyo- 
dorsalis und Hyoventralis) zusammensetzt, die als Fortsetzung 
des Riickenmuskels und des Rectus zu betrachten sind, ist dadurch 
zu verstehen, dass Schneider offenbar schon die oben erwihnte 
Fortsetzung der inneren Schichte (von ihm als Riickenmuskulatur 
aufgefasst) in die Halsmuskulatur bemerkte.” 
Text-figure 2. 
Transverse section through the caudal region of a typical Teleostean with the 
contiguous. body-surface, to show the relations to one another of six con- 
secutive myomeres. The right side of the figure represents the anterior 
portion of the section. (Generalised, mainly from Cottus scompius:) 
M.D., Mesio-dorsal portion; 1Z.V., Mesio-ventral portion ; Z.D., Latero- 
dorsal portion; Z.V., Latero-ventral portion; 1-6, consecutive myomeres, 
the first is anterior; f.s., horizontal septum ; /./., lateral line (with “red 
fibres”? on either side of it); @ftm., anal fin-muscle; d.fm., dorsal fin- 
muscle. 
T, too, have noted this double condition of the hyo-cleithrale in 
certain Teleosteans (Lophius, Trigla, Zeus). My observations 
* A yevised term more accurately descriptive of the muscle hitherto known as 
hyo-clavicularis (synon. Stenohyoideus, Cervicalis profundus, etc.). 
