67*1 MASSES. U. C. \. WTNBLl AND F. G. PARSONS ON [Dec. 17, 



at our disposal into two groups accoi'ding to the insertion of the 

 muscle, the reader must bear in mind that many of the cases in 

 which the insertion is said to be into the cephalo-humeral are 

 possibly the result of imperfect dissections, and this applies to 

 some of our own dissections as well as to those of other observers, 

 for at first we failed to realize the amount of careful cleaning which 

 is necessary to satisfactorily display the posterior attachment of the 

 omo-trachelian. On the other hand, we do not feel justified in 

 asserting that the muscle never ends by completely fusing with 

 th.' cephalo-humeral. 



in the following animals the omo-trachelian was traced to the 

 fascia over the scapula and the scapular spiue — Hippopotamus 

 (1, 3), Pig (4, 5, 7, 11), Peccarv (1-1), Ox (33), Sheep (38), 

 Mouflon (45). Goat (46). Duiker-bok (49), Tapir (52), Hyras 

 (68). 



In the following the muscle is said to blend with the cephalo- 

 humeral :— Pig (6), Chevrotain (21), Brocket (27, 28), Ox (35), 

 Sheep (40, 43), Tapir (54, 55), Ehinoceros (64). In the whole of 

 the above two groups of animals the origin was from the trans- 

 verse process of the atlas, except in the Duiker-bok (49), in which 

 a small slip came from the basioccipital in addition. 



In the Muntjac (26) among the Cervidae, Macalister says that 

 the muscle was absent, and in our own specimen of Cervus (25) 

 we failed to find it ; possibly in these animals the incorporation ol 

 the omo-trachelian with the cephalo-humeral has become complete 

 and the origin from the atlas suppressed. 



In the Giraffe (29), Joly and Lavoeat point out that the length 

 of the neck has caused the origin of the muscle to shift back to 

 tVe transverse processes of the sixth and seventh cervical vertebrre ; 

 and there is every reason to believe that Murie (XXXII.) verified 

 this, since he carefully studied the above authors' paper, and onl\ 

 drew attention to points in which his animals differed from theirs 

 or to facts which they had omitted. 



In the Equidse (56, 57, 58, 59) the origin is from the anterior 

 four cervical transvei'se processes, and the muscle in this case 

 certainly does fuse posteriorly with the cephalo-humeral in a very 

 complete manner. 



In the Elephant, Miall nnd Greenwood) XXIX.) apparently failed 

 to notice the muscle, but we believe it is there because Anderson 

 (XXVII.) describes a part of the masto-humeral (cephalo-humeral) 

 which he says may be regarded as a separate muscle, and which 

 rises from the basioccipital to be inserted into the anterior border 

 of the scapular spine as well as into the fascia covering the 

 deltoid. This insertion is clearly that of the omo-trachelian, and 

 the origin from the basioccipital we h.nve already shown exists 

 in the Duiker-bok (49), but further details of the muscle are badly 

 wanting in the Elephant. 



In the Pig, Peccary, Brocket, Sheep, Duiker-bok, and Hyra.x 

 we found the nerve-supply coming from the spinal accessory. 



Scalenus ventratis. — The arrangement of parts in the Ungulates 



