REPORT ON THE SPHENISCID^. 65 



Relations. — Its origin lies in contact with the outer side of that of the rectus anticus 

 major. The belly of the muscle separates the rectus anticus major in front from the rectus 

 lateralis behind. 



Nerve sui^ply. — Branches from the anterior divisions of the second and third cervical 

 nerves. 



Variations. — In Aj^tenodytes longirostris, as well as in Splieniscus demersus, the 

 origin of the muscle is limited to the second, third, and fourth cervical vertebrse. 



7. Rectus capitis posticus minor. 



Kleiner Kopflieher, Merrem. 



Der kleine hintere gerade Kopfmuskel, Tiedemann, p. 283, No. 4. . 

 Le petit muscle droit posterieur, Cuvier, voL i. p. 237. 

 Troisieme poste'rieur de la tete, Meckel, vol. vi. p. 12. 

 Mecttis capitis posticiis minor, Selenka, vol. vi. p. 99, No. 16. 

 ' Petit droit, Gervais and Alix, p. 14. 



Attachments. — This is a very small muscle, which is inseparably connected with that 

 of the opposite side. It arises from the arch of the atlas, and passing forwards is 

 inserted into the central projection of the occipital bone close to the foramen magnum. 



Action. — This muscle extends the skull upon the atlas. 



Relations. — The muscle is concealed by the splenius capitis, and rests upon the 

 posterior occijiito-atlantal ligament. 



Nerve supiily (?) 



id) Muscles of the Tail. 

 1. Levator coccygis. 



Les releoeurs du coccyx, Vicq d'Azyr, 1774, p. 496, No. 1. 



Der grosse Schtcanzheber, Merrem. 



Der Steissheinheber, Wiedemann, p. 82. 



Der Heher des Steissheinn, Tiedemann, p. 292, No. 1. 



Elevateur et Ahducteur de la queue, Meckel, vol. vi. p. 14, No. 1. 



Levator catidce, Owen, p. 30. 



Levator coccygis, Selenka, vol. vi. p. 100, No. 21. 



Sacro-coccygien superieur and Transversaire-epineux, Gervais and Alix, p. 15. 



Attachments. — This muscle has been described by Gervais and Alix as consisting of 

 two distinct portions. The first, anterior, and stronger portion (sacro-coccygien supdrieur 

 of Gervais) arises from the spines and transverse processes of the last four sacral vertebrse, 

 as well as from the adjacent surface of the ilium and ischium. The muscular belly 

 terminates on several tendons, which, passing obliquely backwards and upwards, are 



(ZOOL. CHALL. EXP. — PAET XVIII. — 1883.) S 9 



