■ ■ -^- 82 — 



the posterior root of the same nerve. Running forward, and soon separating, each root swells slightly 

 into an elongated intracranial ganglion, from wliich the lateralis trigemini and lateralis facialis nerves 

 respectively arise. 



In the other fishes of the group the roots and ganglia of the complex conform closely to those 

 in Scorpaena, excepting only in the number and arrangement of the bundles of fibers that arise from 

 the communis ganglion. In the one specimen of Lepidotrigla that was examined, all of these latter 

 fibers arose from the ganglion as a single bündle which immediately separated into two parts, both 

 of which traversed the facialis foramen and entered the trigemino-facialis chamber. One of these 

 two parts is the palatinus facialis which turns forward in the trigemino-facialis chamber and issues 

 through the trigeminus opening of that chamber. The other part separates into two bundles as soon 

 as it enters the chamber, one of these bundles joining the trigeminus nerves and containing all the 

 communis fibers destined to those nerves, while the other bündle contains the fibers destined to 

 Jacobson's anastomosis and the truncus hyoideo-mandibularis facialis. In Dactylopterus one bündle 

 of fibers traverses the trigeminus foramen, and another the facialis foramen, the latter bündle sepa- 

 rating into three parts, the facialis branch to Jacobson's anastomosis, the ramus palatinus and the 

 communis component of the truncus hyoideo-mandibularis facialis. 



The fact that all of the communis fibers destined to the nervus trigeminus issue from the cran- 

 ial cavity, in Lepidotrigla, by the facialis foramen might be considered as evidence in favor of the 

 assumption that the communis fibers of the V — VII complex of that fish all belong to the nervus 

 facialis; but it must not be overlooked that the fibers destined to the trigeminus all issue from the 

 trigemino-facialis chamber by the trigeminus opening of that chamber, the fibers that issue through 

 the facialis opening of the chamber all going to the nervus facialis. It is also to be noted that on one 

 side of the 55 mm Scorpaena, and also on one side of the adult Scorpaena used for figure 28, a con- 

 dition is found that is intermediate to that found on the other side of those two specimens and to that 

 found in Lepidotrigla. These differences in the course of these fibers would all be explained by the 

 assumption that the entire trigemino-facialis ganglionic complex was, in the immediate ancestor or 

 ancestors of all teleosts, enclosed in a trigemino-facialis chamber in the cranial wall, as it actually 

 is in Amia, and that the perforations of the inner wall of this chamber are not necessarily of seg- 

 mental importance. But while there is much in favor of these assumptions it is to be noted: that 

 in the Plagiostomata, according to Stannius, ('49, p. 32), the ganglion of his third root of the trigemino- 

 facialis complex is always extracranial, while the ganglion of his first root, is intracranial; and that 

 in Petromy^on, according to Johnston ('05 b)j the gangUon of the facialis has its general cutaneous 

 and communis components intracapsular, but its lateralis components extracapsular in position; 

 and that the descriptions lead one to conclude, although it is not definitely so stated, that the ganglion 

 of the trigeminus is extracapsular. 



b. Truncus Ciliar is Profund i. 



The truncus ciliaris profundi is the only nerve that arises from the profundus ganglion. Running 

 forward in the cranial cavity it usually issues, in Scorpaena, through a special foramen in the proötic, 

 but in two instances it was found traversing the oculomotorius foramen with the oculomotorius. 

 In Cottus, Trigla and Lepidotrigla, in all the specimens examined, it issued through a foramen that 

 lies close to the trigeminus and facialis foramina, these two latter foramina lying, the former 

 dorso-anterior to the latter and the profundus lying between and immediately anterior to them. 



