70 SUPPLEMENT ON 



often occurs, mutually crossing each other, from the inferior 

 ray of a membrane to the anterior extremity of the opposite 

 branch of the hyoid. They extend the membrane, and bring 

 it nearer to that of the other side. There are besides small 

 particular muscles on each ray ; but not in all species. 



The muscles of the branchial and pharyngeal apparatus 

 may be divided into several groups ; some suspending it to 

 the cranium, others to the humeral bone, others to the hyoid, 

 while some are proper to the organ itself, uniting its different 

 parts together. One bundle is attached to the cranium, at 

 that part of the great ala and petrous bone which is beneath 

 the articular groove presented to the temporal by the posterior 

 frontal, and the mastoidean. It is composed of two ranges of 

 bands, four external, and two internal ; the first inserted on 

 the back of the four branchial arches, the second to the two 

 pharyngeals. These muscles raise the apparatus and dilate 

 the gills. Another bundle attached to the cranium behind 

 the depressor of the operculum, and extending to the extre- 

 mity of the mastoidean, consists of two bands, one anterior, 

 which reaches the fourth arch, and the other posterior, which 

 extends to the tissue of the pharynx. A third bundle consists 

 of a considerable muscle, passing from the third superior pha- 

 ryngeal, through the fibres of the pharynx, obliquely to the 

 spine. There is a particular muscle attached to the superior 

 part of the second arch, and to the side of the basis of the 

 cranium. Three muscles act upon the apparatus by means of 

 the inferior pharyngeal, to which they are attached; and be- 

 tween these muscles and their fellows of the opposite side 

 the pericardium and heart of the fish are placed. The 

 muscles proper to the apparatus are four oblique on each side, 

 from the single chain of bonelets to the lower part of each 

 arch ; and also three superior transverse from the pharyngeal 

 to the nearest part of the arch. There is besides one inferior, 

 from one pharyngeal to the other. 



