THE CRANIAL MUSCLES AND CRANIAL AND 

 FIRST SPINAL NERVES IN AMIA CALVA. 



EDWARD PHELPS ALLIS. 



For several years past I have been engaged in an anatomical 

 investia:ation of the cranial nerves in Amia calva. The 

 manuscript descriptive of the larger part of the work has been 

 practically ready for publication for two years or more. The 

 publication of it has, however, been delayed awaiting the 

 completion of the numerous drawings necessary for illustra- 

 tions. These drawings and the final dissections from which 

 they are being made are being prepared by Mr. Jujiro Nomura, 

 my exceedingly able and valuable assistant. I now find, unex- 

 pectedly, that several of the dissections and drawings already 

 finished are wanting in definiteness and completeness, and 

 must accordingly be remade, necessitating a further delay of 

 several months. I therefore publish now the following short 

 summary of certain of the results obtained. 



1. The canalis transversus of selachians (Gegenbaur) is, in 

 Amia, a groove extending transversely from orbit to orbit 

 immediately in front of the transverse cartilaginous " Wulst " 

 (Sagemehl), and the two ossifications of that " Wulst " that 

 represent in Amia the basisphenoid of teleosts (Bridge). 



2. The " Augenmuskelkanal " of Amia and teleosts is not 

 therefore the canalis transversus of selachians, as Sagemehl 

 concludes it to be. In Amia it is a cavity or space formed in 

 late larval stages around the hypophysis and saccus vasculosus ; 

 and entrance to it, for the muscles of the eye, has been 

 acquired along a canal that gives passage to two branches of 

 that portion of the orbital venous sinus that lies in the upper 

 lateral chamber of the eye-muscle canal. Of these two 

 branches, one arises in the choroid gland and is almost directly 

 continuous with the other, which arises from the hypophysis 

 and connects under that organ with the corresponding vein of 

 the opposite side of the head. 



