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CAPTAIN E. W. SHANN ON 
of the skull (exoccipital, otic recess, and post-temporal). In some Teleosteans a 
small superficial branch of this muscle is attached to the supraclavicle ( Blennius 
pholis), or to the cleithrum ( Cottus scorpio), where it is inserted on the posterior 
border of the backwardly directed spine in which that bone ends. 
In Periophthalmus the mesio-dorsal portion of the lateral muscle gives a small 
branch to the upper border of the post-temporal ; but this is exceptional in the 
Teleostei. 
Where this muscle is present the r.l.v.p., next to be described, is wanting, 
and vice versa. 
( b ) Retractor later o-ventralis pectoralis. Retractor scapulae, Owen. — M‘Murrich 
(60) states that the latero-ventral portion of the lateral muscle (his third portion) 
disappears in Amiurus before reaching the shoulder girdle ; such is the case in some 
other Teleosteans, but in the majority a small bundle of fibres, undoubtedly belonging 
to this portion, is attached to the upper extremity of the cleithrum, or to the supra- 
clavicle ( Trigla gurnardus), or to both ( Lophius piscatorius). The muscle is 
frequently flat and fan-shaped. 
In Lophius this muscle has undergone most remarkable modifications, prob- 
ably in accordance with the extraordinary mobility of the limbs in that form. 
Hamburger (42) has already given an account of the musculature of the fore limb 
of Lophius ; but, as his description is incomplete, and he has neither named nor 
illustrated the individual muscles, and as the case is of peculiar interest, I shall deal 
with it here in detail. Fig. 22 shows the dorsal aspect of the right shoulder after 
removal of the skin, the latero-dorsal portion of the lateral muscle, and the retractor 
mesio-ventralis pectoralis superior : the various parts of the r.l.v.p. are numbered i-v. 
Part i is a strap-like muscle inserted mainly on the ventral surface of the supra- 
clavicle, but in part also on the dorsalmost extremity of the cleithrum (ventral aspect). 
Part ii is a strap-like muscle inserted on the dorsalmost portion of the cleithrum 
above the origin of i. It is also distinguished by its darker colour. 
Part iii is a flattened cylindrical mass inserted in a slight hollow on the ventral 
aspect of the cleithrum immediately behind the glenoid border. It passes inwards 
and downwards, between parts ii and v, so as to cover the peritoneum. 
Part iv is a strap-like muscle given off by part v at a level defined by producing 
the long axis of the supraclavicle, and inserted into part iii at a level slightly adaxial 
to the backwardly directed process of the cleithrum. 
Part v is a powerful strap of muscle inserted on the ventral aspect of the abaxial 
third of the horizontal stem of the cleithrum. It curves abruptly inwards and 
then upwards. 
Parts i, ii, and v do not go to form part of the latero-ventral body muscle, but 
take origin by a fascia along the lateral line. It might be supposed that these 
muscles belonged tc the latero-dorsal portion, but the fact that part v is blended 
with part iii (undoubtedly ventro-lateral) through the medium of part iv, indicates 
