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and directly anterior to the low swelling of the acusticus part of the tubercidum acusticum; the 

 anterior root of the acusticus spreading, and entering the medulla both dorsal and ventral to the level 

 of the point of exit of the motor root of the facialis. After the root emerges from the medulla it lies 

 dorso-anterior to the anterior root of the acusticus, between it and the overlying lateralis facialis 

 root, but it soon passes up along the lateral surface of the latter root and reaches its dorsal surface. 

 There it continues forward closely applied to the lateralis facialis and issues, with that nerve, through 

 the facialis foramen. As the two nerves pass through the foramen, of shortly before, they receive a 

 large bündle of fibers from the communis ganglion, the three components together forming the 

 truncus facialis. This truncus does not traverse the trigeminus ganglion, passing postero-ventral 

 to that ganglion. As in Menidia, it contains no general cutaneous component. 



The next posterior root is the communis root. This root leaves the medulla alniost directly 

 dorsal to the motor facialis root, its point of origin lying immediately dorsal to the low, acusticus 

 swelling of the tuberculum acusticum, and immediately anterior to the low, lateralis swelling of 

 the same structure. Immediately after issuing from the medulla it lies wedged in between the 

 lateralis trigemini and lateralis facialis roots, and, anterior to that point, lies lateral and then ventral 

 to the trigeminus root as that root passes between the two lateralis roots. It then swells into a large 

 pear-shaped intracranial ganglion, the large end of the pear directed antero-laterally, and the ganglion 

 occupying the ventral or ventro-mesial portion of the large root-stalk of the complex. From the 

 anterior portion of this ganglion, three bundles, or groups of sub-bundles of fibers arise, their arrange- 

 ment being somewhat different on the two sides of the one specimen in which they were traced. One 

 of these bundles is the ramus palatinus facialis which runs downward in the cranial cavity and, per- 

 forating the base of the proötic bridge, enters the myodome. A second one of the three bundles is 

 a group of sub-bundles which traverses the trigeminus foramen ; containing two separate sub-bundles 

 on one side of the specimen and three on the other. One of these sub-bundles enters and traverses 

 the trigeminus ganglion, going mainly if not entirely to the ramus oticus; the other one or two sub- 

 bundles traversing the ganglion to enter the truncus maxillo-mandibularis trigemini. The third 

 bündle that arises from the main ganglion traverses the facialis foramen and it was single on one side 

 of my specimen but double on the other. On the single side the entire bündle entered the truncus 

 facialis, a small brauch being immediately sent to Jacobson's anastomosis. On the double side, one 

 of the two sub-bundles went to the truncus facialis and Jacobson's anastomosis, the other sub-bundle 

 running upward in the trigemino-facialis Chamber and entering the truncus maxillo-mandibularis. 

 This latter arrangement was also found on one side of the adult specimen used for figure 28, and 

 hence is probably not unusual. 



The communis root of Scorpaena thus diffcrs from that of Menidia only in that two separate 

 bundles of fibers, instead of a single one, go to the truncus maxillo-mandibularis. Whether both 

 bundles go to the ramus maxillaris, or one to that ramus and the other to the ramus raandibularis, 

 I could not determine. Scorpaena further differs from Menidia in the absence of any intracranial 

 recurrent communis nerves, and Trigla, Lepidotrigla and Dactylopterus all agree with Scorpaena 

 in this respect. In Cottus, on the contrary, there is an important intracranial recurrent brauch. 



The next two roots of the complex, in Scorpaena, the two that have the most posterior apparent 

 origin from the medulla, are the roots of the lateralis trigemini and lateralis facialis nerves. These 

 two roots arise as a single root from the tuberculum acusticum immediateh' posterioi^ to the communis 

 root and immediately dorso-posterior to the anterior root of the acusticus, between that root and 



Zoologica. Heft 57. jl 



