EEPORT ON THE SPHENISCID.5!;. 57 



3. Extensor magnus colli. 



Long extenseur du cou, Vicq d'Azyr, 1773, p. 580, No. 1. 

 JJer grosse Halsstrecker, Tiedemann, p. 287, No. 2. 

 Vielarmiger Halsmwikel, Merrem. 

 Grosser Halsstrecker, Wiedemann, p. 76. 

 Cervical ascendant, Meckel, vol. vi. p. 5, No. 1. 

 Longtis colli posticus (part of), Owen, p. 27. 

 Longus colli posticus, Selenka, vol. vi. p. 95, No. 4 

 Long posterieur du cou (part of), Gervais and Alix, p. 14. 



Attachments. — This muscle arises by means of a stout flattened tendon from the 

 spinous processes of the last cervical and first three dorsal vertebrae. The muscular 

 fibres pass obliquely forwards and outwards, and are inserted by means of separate 

 slips into the tubercles surmounting the posterior articular processes (hyperapophyses of 

 Mivart ') of the fourth to the eleventh cervical vertebrae inclusive. 



Action. — This muscle is the most powerful of the numerous extensor muscles of the 

 neck. 



Relations. — At its origin the extensor magnus is united with the muscle of the 

 opposite side. As it passes forwards it is separated from its fellow by the two lesser 

 extensors of the neck. To its outer side is the cervicalis asceudens. 



Nerve supply. — Branches from the posterior divisions of the lower cervical 

 nerves. 



Variations. — In Aptenodytes lo7igirostris the insertion of this muscle extends from 

 the fifth to the twelfth cervical vertebrae, in Spjheniscus magellanicus from the sixth to 

 the ninth, and in Eudyptes chrysolophus and Spheniscus demersus from the third to the 

 ninth cervical vertebrae inclusive. 



4. Splenius colli. 



Der Strecker des Trdgers, "Wiedemann, p. 76. 



J)er Strecker des Trdgers, Tiedemann, p. 286, No. 1. 



Splenius du cou, Meckel, vol. vi. p. 7, No. 3. 



Long posterieur ducou (part of), Gervais and Alix, p. 14. 



Attachments. — The splenius colli arises by means of a number of separate muscular 

 slips from the spinous processes of the third, fourth, and fifth cervical vertebrae, as well 

 as from the arches of the sixth to the ninth cervical vertebrae inclusive. (The latter do 

 not possess spinous processes). The muscular fibres converge as they pass forwards, and 

 are inserted into the posterior articular process (hyperapophysis) of the second cervical 

 vertebra. 



' Trans. Zool. See, vol. viii., pt. 7, 1874. 



(ZOOL. CHALL. EXP. — PART XVIII. 1883.) S 8 



