1905.] ANATOMY OF THE LEATHERY TURTLE. 295 



The muscle can be separated into three strands. The most 

 anterior is the part inserted upon the skull, and forms a very 

 definite muscle that passes from the mid-line of the thi-oat just 

 internal to the middle cornu of the hyoid. The other two strands 

 are thinner and less defined. All three parts form towards the 

 mid-line of the throat a fairly continuous sheet, whose hinder 

 part extends back beneath the clavicular portion of the deltoid to 

 the clavicle. 



Coraco-hyoicleus (text-figs. 58-60. 20). — Origin : from _ the 

 antero-dorsal boi-der of the coracoid about its middle. Insertion : 

 upon the ventral surface of the body of the hyoid. In its course 

 it passes dorsal to the clavicle. 



Coraco-ceratohyoideus (21). — This muscle was continuous with 

 the longitudinal muscles of the oesophagus. No origin _ from the 

 coracoid was seen (it may have been missed). Insertion : into 

 the ventral surface of the body and middle and posteiior cornua 

 of the hyoid. It is stated (Hofi'mann, p. 82) that this muscle is 

 peculiar to Chelone. 



Genio-hyoideus (22). — Origin: the anterior two-thirds of the 

 inner surface of the mandible, just above the insertion of the mylo- 

 hyoid. Insertion : upon the anterior iDorder and ventral surface 

 of the middle cornu of the hyoid. 



Gerato-maxiUaris (23). — Origin : the tip of the middle cornu of 

 the hyoid. Insertion : upon the inner surface of the angle of the 

 jaw, just above the insertion of the squamoso-maxillaris. 



Geratoglossus (24). — Origin : the ventral surface of the proximal 

 end of the middle cornu of the hyoid. Insertion : into the 

 tongue. 



Dorso-occijntis (text-fig. 55. 26).— -Origin : by tendon frona the 

 ventral surface of the second dorso-lumbar vertebra. Insertion : 

 by a narrow tendon to the base of the skull 3-5 cm. in front of 

 the foramen magnum. 



A flattish muscle, lying just ventral to the roots of the brachial 

 plexus. It passes dorsal to the outer end of the posterior cornu 

 of the hyoid, and at this point forms a narrow tendon. 



In most Chelonia (Hofi'mann, p. 83) this muscle appears to 

 have a more extended origin, including usually several dorso- 

 lumbar vertebra?, as well as the ribs connected with them. In 

 its insertion it resembles the dorso-occipitis of Ghelys and 

 Ghelemys. 



Gollo-squamosus (text-fig. 55. 28).— Origin : from the lateral 

 parts of vertebrae ii., iii. Insertion : upon the squamosal close 

 above the dilator tubfe. 



Longus colli (text-fig. 55. 29).— A complex mass of muscle 

 covering the ventral surface of the cervical vertebrae. Upon its 

 surface are a number of half independent tendinous slips. The 

 detailed origins and insertions of its various parts were not made 

 out. 



There was no origin from the anterior ribs or nuchal plate such 

 as seems to occur generally (Hofiinann, p. 84). 



