willard: cranial nerves of anolis carolinensis. 37 



is a perfectly distinct muscle, having its origin under cover of m. 

 cerato-mandibularis 1 about half way along the jaw, and being in- 

 serted near the distal end of the cerato-hyal instead of the cerato- 

 branchial (Plates 5, 6, figs. 13-19). No corresponding muscle has 

 been found in any of the descriptions of saurians. 



The innervation of the above three muscles is from nerve XII, 

 which passes across the deeper surface of the first described portion 

 (ker-mdJ); two branches are given oft' here, the anterior of which 

 runs cephalad to supply also the anterior muscle (kcr-md.^). The 

 small bimdle (kcr-md/) is inner\ated by an independent ramus, 

 directly from XII. 



M. ceratohyoideus = hyoglossus (hy-gls.). This is a muscle (Plates 

 6, 6, figs. 13-19) extending between the first and second horns of the 

 hyoid apparatus (i. e., between cerato-hyal and cerato-branchial I). 

 The attachment on the latter is more extended than that on the cerato- 

 hyal, so that the muscle sheet is much thinned posteriorly, consisting 

 of fine bands somewhat separated from one another. The pharyngo- 

 laryngeal branch of IX + X (phx-Iar.^) passes along the superficial 

 face of this muscle between it and m. genioglossus. It is innervated 

 by motor fibers carried in this branch (Plate 2, fig. 5), which might 

 indicate either a visceral origin for the muscle or the presence of 

 fibers from XII in the nerve. 



M. omohyoideus (omo-hy.). This (Figs. F-G; Plates 6, 7, figs. 

 16-24) has its origin on the shoulder girdle along the clavicle, ex- 

 tending to near the median line, and passes forward as a broad sheet 

 slightly converging with its mate to be inserted on the cerato-branchial 

 I along almost its entire length and also on the basihyal. The fibers 

 with the latter insertion form a bundle which, through a difference in 

 direction, differentiates the superficial part (omo-hy.) from the deeper 

 part {omo-hy. prf.), a distinction of slight importance in this form. 



M. sterno-hyoideus {sin-hy.). The removal of m. omohyoideus 

 uncovers a muscle (Plate 5, figs. 13-15) which takes its origin from the 

 sternum, the muscles of the two sides having a common median origin. 

 The insertion is along the cerato-branchial I, co-extensive with that 

 for the omohyoideus, but at a deeper level. At the angle of cerato- 

 branchials I and II (Plate 5, fig. 13) the fibers of the median edge of 

 sterno-hyoideus turn mesad to be inserted on the base of cerato- 

 branchial II, on both the ventral and dorsal sides. The median edges 

 of these muscles are the thickest and they spread out fan-shaped from 

 median origin to insertion on the cerato-branchial I. A little of the 

 trachea {tr.) is exposed just caudad to the l^asihyal, as is shown in 

 Figure E. 



