896 MR. F. E. BEDDARD OX THE ANATOMY [Dec. 15, 



below) and which is perfectly distinct from the rhomboideus of 

 liana giq^'pyi to which I have just referred. The muscle is inserted 

 on to a considerable area of the supi'ascapnla and is in contact in 

 front with the insertion of the I'homboideus, which is in its tui'n 

 in contact with the insertion of the cncullaris. At its origin the 

 muscle is connected with the tendinous intersection of the 

 longissimus dorsi as well as with the trans\'erse process of the 

 fourth vertebra. Between this muscle and the next to be men- 

 tioned lies the anterior lymph heart which is described on another 

 page *. This next muscle arises from the end of the transverse 

 process of the third vertebi^a and is distinctly composed of two 

 parts. Each of these is a flat sheet of muscular fibres. 



The two sheets are perfectly distinct at their origin. For the 

 outer of the two does not extend so far along the surface of the 

 cartilage posteriorly as does the inner muscle. At their insertion, 

 however, close to that of the retrahens scapula^, there is no dis- 

 tinction between the several layeis of this muscle, which must 

 therefore be regarded as simply douljle-headed. It differs there- 

 fore from the transverso-scajndaris ierilus or serratus (Ecker) of 

 Rana escidenia, with which I believe it to be homologous. The 

 insei-tion of this muscle is in contact with that of the reti-ahens 

 scapulae. The fourth muscle is not a flat muscle like the last 

 two, but is narrow and more or less oval in ti-ansverse section. 

 It arises independently of the last muscle from the anterior 

 edge of the free end of the transvei-se process of the third 

 vertebra, and is inserted quite away from the serratus near the 

 anterior border of the suprascapula outside of the insertion of 

 the levator anguli scapula\ This muscle is not mentioned by 

 Ecker, unless, indeed, it is this which is the transverso-scapularis 

 tertius. 



The remaining muscle of the " serratus " series is obviously the 

 homologue of the transverso-scajyvlaris major (Ecker) of Rana 

 esculenta, and is the only muscle of the series which is inserted 

 upon the scapula. As in R. esculenta, it arises by two heads, 

 one from each transverse process of vert. 3 & 4. That arising 

 from the transverse process of the fourth vertebra is very much 

 the larger and both heads are entirely fleshy. The insertion of 

 this muscle on to the scapula lies between the insertions of the 

 sterno-cleidomastoid and the protrahens scai^ula?, which are tlie 

 two head muscles of the scapula corresponding to the single head 

 muscle of the suprascapula referred to above t. 



When iir Hemisus the latissimus dorsi has been cut through 

 and reflected, two muscles belonging to the serratus series aie 

 exposed throughout their entire leng-th and a third very nearly 

 so. The two which are fully exposed belong to the suprascapula, 

 and the third is very obviously the equivalent of the transverso- 

 scapularis major which is inserted on to the scapula. 



* Firfep. 930. 



t The stei-nocleidomastoideus of i2.. ^'k/)^//? really consists of two parts, a mucli 

 larger part and a smaller wliicli is inserted separately bj- a longish tendon. 



