— 105 — 



bounded as usiial by the sphenotic, pterotic, exoccipital and basioccipital, and its ventral portion 

 is overlapped externally by the paraspbenoid. From the opisthotic it is separated by a considerable 

 interval. 



Immediately anterior to the base of the postorbital process, the proötic is perforated by two 

 or three foramina, which transmit the profundus, trigeminus and faciahs nerv es: the profundus 

 issuing alone through one of the foramina, where there are three, but issuing with the trigeminus 

 where there are but two. The profundus foramen, when present, is a small canal which, running 

 inward, either opens into the trigeminus foramen, or close to that foramen on the inner surface of 

 the skull. The trigeminus foramen is the largest of the two or three and lies antero-dorsal to the 

 facialis foramen, both foramina opening into a trigemino-facialis recess on the internal surface of 

 the proötic, similar to the recess described in Scorpaena. This recess in Cottus is, however, relatively 

 larger than in Scorpaena, and its floor as well as its roof is formed by a thin shelf-like Hange of bone. 

 The recess lodges, as in Scorpaena, the profundus ganglion and the ganglia formed on the communis 

 and lateralis roots of the trigemino-facialis complex. The communis ganglion is a large, pear-shaped 

 ganglion, and from it, two intracranial nerves arise. One of these nerves is the ramus palatinus faci- 

 alis, which runs downward forward and mesially, perforates the horizontal ledge that forms the fioor 

 of the trigemino-facialis recess and then the prepituitary portion of the mesial process of the proötic, 

 and so enters the myodome at its extreme dorso-lateral corner. The other nerve runs upward and 

 backward, perforates the thin shelf of bone that forms the roof of the trigemino-facialis recess, and 

 then continues upward and backward along the edge of the bony anterior wall of the labyrinth recess, 

 until it reaches the roof of the cranial cavity. There it turns backward and mesially along the internal 

 surfaces of the frontal and parieto-extrascapular, passes between those bones and the supraoccipital, 

 and issues on the dorsal surface of the skull close to its hind edge and close to the median line. On 

 one side of the one specimen examined, the thin roof of the trigemino-facialis recess was perforated 

 by two foramina, the communis nerve just above described there doubtless arising from its 

 ganglion by two Strands. This nerve, in its general course, closely resembles the 80-called lateralis 

 accessorius of Gadus and Silurus, and, like the palatine, must consist largely, if not entirely of 

 communis fibers. 



In addition to these two intracranial nerves, two large nerve trunks and the smaller truncus 

 ciliaris profundi arise from the complex and issue by the two or three foramina in the proötic. 

 One of the two trunks is the root of the trigeminus accompanied by lateralis and communis 

 fibers, and this root is closely accompanied by the truncus ciliaris profundi. The other trunk is the 

 root of the facialis accompanied by lateralis and communis fibers. The truncus ciliaris profundi separ- 

 ates from the root of the trigeminus while still inside the cranial cavity and either issues through 

 the trigeminus foramen, or through a separate and independent profundus foramen. It then enters 

 the internal jugular canal through its posterior opem'ng, and traversing that canal enters and traverses 

 the anterior end of the myodome, and so issues in the orbit. The root of the trigeminus swells into 

 a ganglion either as it traverses its foramen or whoUy but immediately beyond that foramen, the 

 trigeminus ganglion thus being largely or wholly extracranial in position. The facialis passes close 

 to the hind end of this extracranial ganglion, and, as in Scorpaena, receives from its hind end a large 

 communicating brauch. Associated with the trigeminus ganglion and lying immediately ventral 

 to it, there is, as in Scorpaena, a large sympathetic ganglion, but this ganglion here lies on the external 

 surface of the proötic. The jugular vein and external carotid artery both come into the same rela- 



Zoologica. Heft 57. 14 



