230 Mr. J. Wood on Variations in Human Myology, [June 21, 



was implanted upon the tendon in the usual manner. The second decus- 

 sated with its fellow on the opposite side, and each became attached to a 

 part of the digastric fossa on the opposite half of the mandible, as given in 

 the author's first paper, and described bj Henle and other anatomists. 



3. Cleido-occipital. — The author has ventured to bestow this name upon 

 a muscle which proved, when looked after, to be so common that not less 

 than eleven specimens were found out of the thirty-four subjects. It will 

 be best understood by reference to fig. 7 «, in the subject of which it was 

 found in conjunction with a sternoclavicular muscle. It is placed along 

 the hinder border of the sterno-cleido-mastoideus, usually separated, how- 

 ever, by a distinct areolar interval from both the sternal and clavicular 

 fibres of this muscle. It is attached below to the junction of the inner 

 and middle thirds of the upper border of the clavicle, and above to the 

 superior curved line of the occipital bone, close to the origin of the trapezius 

 muscle. It is described by Meckel (Handbuch der mensch. Anatomic, 

 1816, p. 474) as an accessory to the sterno-cleido-mastoid sometimes met 

 with. It may be considered as a lateral extension and separation of part 

 of the clavicular fibres of the sterno-cleido-mastoid^ which, in the normal 

 arrangement, are crossed and entirely covered at the upper part by the 

 sternal portion, and do not extend at their insertion beyond the mastoid 

 portion of the temporal bone. The author has found that in the Guinea- 

 pig and some other Rodents it constitutes a separate muscle, entirely distinct 

 from the sterno-mastoid, carrying with it the whole of the clavicular fibres 

 of the sterno-cleido-mastoideus. In the Dog and Cat, and probably in the 

 other Carnivora, it forms part of the long muscle, the cephalo-humeral. 

 In these animals the cleido-mastoid is a distinct muscle, joining with 

 the cephalo-humeral at the rudimentary clavicle. In the Hedgehog, on the 

 other hand, the cleido-mastoid is blended with the sterno-mastoid, while the 

 cleido-occipital is placed as a distinct muscle behind it. In the Apes and 

 Monkeys it is always present, but continuous with the hinder border of the 

 true sterno-cleido-mastoid, with a more or less distinct intermuscular space*. 

 The above peculiarities of its comparative anatomy, and the fact of its separate 

 attachment to the occipital bone, instead of the mastoid portion of the tem- 

 poral bone, have induced the author to propose the name here given to it. 



4. Of the single specimens in this column the levator claviculce was in 

 most respects the counterpart to that given in the author's last paper ; 

 but it was found only on the left side, arising from the three upper cervical 

 transverse processes in front of the levator anguli scapuloe^ and inserted 

 into the outer half of the clavicle, behind the anterior fibres of the trape- 

 zius. On the opposite side it was not found, but a very distinct cleido- 

 occipital was present. This again was not found on the left side, but 

 appeared to supply the place of the levator claviculce. The costo-fascialis 

 cervicalis, of subject 28, was in every respect like those described in the 



* Meckel describes, in the Marmot, the Squirrel, and some other Eodents, and in 

 some Marsupials, two cleido-mastoids, of which the hinder corresponds entirely to the 

 muscle here called cleido-occipital (Anatomie Compar. 1829-30, vol. vi. p. 163). 



