willard: cranial nerves of anolis carolinensis. 



43 



passes through this muscle and is distributed to the ventral skin 

 region. Three branches of spinal nerves are shown to innervate the 

 cucullaris muscle; their precise relation to particular spinal nerves 

 was not determined owing to apparent anastomoses of rami. No 

 relation that would suggest an innervation from a spinal accessory 

 nerve was established with any nerves anterior to spinal II. 



M. laxator tyvipani of Versluys {lax. tym.). A very small muscle, 

 less than one half mm. in length, extends caudad from the insertion 

 of the tympanic ligament on the extra-columella (Plate 7, figs. 21, 22). 

 Its fibers end on the connective-tissue covering of the parotic process. 

 The motor component of nerve VII passes ventral to the posterior end 

 of this small bundle and in contact with it. The series of sections did 

 not show with certainty the innervation of this muscle from motor 

 VII, but a few fibers are given off from the main nerve bundle which 

 in all probability accomplish such innervation. This is the more 

 probable because there is no other nerve in the vicinity. Owang to 

 its minute size this muscle was not isolated in dissection, but is a 

 constant feature of the sections. 



This muscle was first described by Versluys ('98) and given the 

 name descriptive of its function. He found it in a number of lizards, 

 all members of the family Gecko- 

 nidae, while he failed to discover ^pJ' .m^phxhr. 



it in as many others, which be- 

 longed to diiferent families. No 

 more positi\-e statement of its in- 

 nervation than is here given for 

 Anolis is contained in Versluys's 

 account. 



M. constrictor venae jugularis 

 internac of Bruner (co'st. vn. j. i.). 

 In Anolis this muscle is found in 

 relations similar to those described 

 by Bruner ( : 07, p. 42) for Phr\Tio- 

 soma. These striate muscle fibers 

 surround the internal jugular vein 

 for a distance of .84 mm. The 

 most anterior fibers, for a distance 

 of .14 mm., have their origin from 

 the most posterior portion of the 

 parotic process (Plate 7, fig. 23, 

 jjrc. pa'ot.) and from the ligamentous extension of it. These anterior 



r/.M 3, Z.I. 



Fig. K. — Frontal projection, dorsal as- 

 pect, of nerves IX and X of the left 

 side, showing the region of the roots 

 and ganglia 'only, together with their 

 connections. Plotted from Anolis, 

 transverse series 48a. Two tumefac- 

 tor nerves (rn{. ini. j.) are given oflf 

 from the ramus pharyngo-larjngeus 

 and one from the ramus superior 

 laryngeus. 



