1869.] MYOLOGY OF MENOBRANCHUS LATERALIS. 457 
which runs beside its fellow of the opposite side from its origin, the 
urohyal, forwards to the mandibular symphysis. 
Fig. 4. 
Muscles of ventral surface: on the right side superficial muscles; on the left 
side deeper muscles, the mylo-hyoidei, pectoralis, and external oblique being 
removed. Also superficial flexor muscles of right pectoral limb. 
B. Biceps. C.B.1 & C. B.2. Coraco-brachialis. _C. H. E. Cerato-hyoideus ex- 
ternus. Ev. O. External oblique. FZ. Flexor longus. G.H. Genio- 
hyoid. M. H.1& M. H.2. Mylo-hyoideus. O. H. Omo-hyoid. P., P.1,& P.2. 
Pectoralis. S. Subelavius. S.H. Sterno-hyoid. S. L. Supinator longus. 
T. Triceps. 
Cerato-hyoideus externus* (figs. 1, 2,3, 4, & 5, C. H. E.). Avery 
voluminous muscle, springing from the whole under surface and 
anterior part of the inner surface of the hyoidean cornu. Passing 
* Fischer, /.c. p. 68. 
