Royal Physical Society. 393 



operculum, and acts principally as a depressor ; and another 

 depressor arises from the posterior margin of the tympanic 

 arch, and is inserted on the under surface of the operculum. 



Two muscles pass from the cranium to the shoulder girdle 

 to pull it forward. One arises from the under surface of the 

 mastoid bone, and is inserted into the inferior process of the 

 scapula ; the other arises immediately outside the former, and 

 is inserted into the upper part of the coracoid bone. 



Small muscles attach the branchial arches to the base of 

 the skull. A ligament passes from the superior junction of 

 the two posterior branchial arches to the coracoid bone, and 

 another from the junction of the two anterior arches to the 

 epi-tympanic bone. 



Muscles of the Body. — The recti abdominis muscles, touch- 

 ing each other in the middle line, extend from the shoulder 

 girdle to the pelvis, and, behind the pelvis, are again con- 

 tinued by two slips which pass from the deep surface of the 

 pelvic bones to the first interspinous bone of the anal fin. 

 External to the rectus, a separate slip of the great lateral 

 muscle passes uninterruptedly from shoulder to tail, and it is 

 at its outer margin that the electric vessels and nerve emerge. 

 It is overlaid behind by the superficial muscles of the anal fin. 

 Separate slips also pass along the dorsum from head to tail, 

 and between them and the main mass is the position of the 

 great lateral branch of the vagus. But what is most worthy 

 of notice is, that the greater number of muscular fibres 

 arising from the coracoid and radio-ulnar bones form a pec- 

 toral muscle, superficial to the other fibres of the great lateral, 

 and digitating with them along the side of the fish opposite 

 the extremities of the fifth, sixth, seventh, and eighth ribs. 

 It is an interesting illustration of the transition from the pri- 

 mitive arrangement in flakes to the formation of distinctly- 

 defined muscles. A strong fasciculus, springing from the 

 occiput, is inserted into the anterior aspect of the spring pro- 

 cess ; and this is the muscle to which Miiller has directed 

 attention, and to which reference is made in a previous place. 



Viscera. — The throat and stomach are large and wide ; so 

 much so, that I found two large shrimps, which had been swal- 

 lowed whole, in the stomach of a specimen four inches long. 



