THE MYOLOGY OF AMIURUS CATUS. 325 
from their original position. According to this view the fibres of 
the first muscle originally ran from the ceratohyal to ceratobr. i., as 
indeed slips do in Hsox and the Cyprinoids ; those of the second from 
ceratobr. i. to ceratobr. i1.; and those of the third from ceratobr. il. 
to ceratobr. iii. This supposition is supported by the fact that in 
other Teleostei there is a fourth obliquus ventralis and no slip be- 
tween ceratobrs. ili. and iv., as in Amiwrus. 
3. Muscutr Transverst VENTRALES, (No. 40, Cuv.; includes 
Transv. pharynger, V etter.) 
These are two in number, exposed by the dissection required for 
the preceding muscles. The anterior one, (Fig. 4, TV‘), extends 
between the ceratobr. of either side of the fourth arch, across the 
lower surface of the branchial apparatus, the posterior (TV) holds a 
similar course between the inferior pharyngeals (ceratobr. v.) 
Action.—They approximate the arches of opposite sides, the an- 
terior one also drawing them slightly downwards. 
The placing of the posterior muscle in a different category from the 
anterior, under the name of pharyngews transversus, is‘quite unneces- 
sary, the two being serially homologous. The origin of these muscles 
is indicated by the representative of the anterior one in the Cypri- 
noids, it being there small and merely part of one of the obliqui 
ventrales. 
4, PwHaryneo-CiavicuLaris Externus, (No. 36, Cuv.; Brancha- 
retractor, Ow.) (Fig. 4, PhE.) 
This muscle and the following one may be seen by the dissection 
required for the hyobranchialis, ef seg., or still better, by dividing a 
specimen longitudinally exactly in the middle line. The hyopec- 
toralis will have to be removed from its attachment to the clavicle 
to expose the origin. The pharyngo-clavicularis ext. arises from 
the upper surface of the clavicle behind the insertion of the hyopec- 
toralis, and passes upwards, forwards and inwards, to be inserted 
into the anterior extremity of the inferior pharyngeal (ceratobr. v.) 
Innervation.—Branch from the first spinal nerve. 
Action.—Draws the pharyngeal backwards, downwards and slightly 
outwards, opposing the transversus and hyobranchialis, 
