340 Journal of Coimparative Neurology. 



municating branch with the r. mandibularis VII [in. VII. 8) 

 mentioned in the account of that nerve. It sends a twig 

 at once into the muscle, which appears to anastomose with 

 the motor twig which enters the muscle near the same 

 point from the ventral division of the infra-orbital trunk. 

 The fibres of this twig, like the rest of those of the com- 

 municating branch, are fine or medium and very different 

 from typical motor fibres. The rest of this nerve runs, as 

 before described, along the ventral surface of the m. 

 adductor mandibulse, becoming progressively smaller cau- 

 dad, and finally joins the r. mandibularis VII. This may 

 be regarded as a sensory nerve for the muscle or as a 

 general cutaneous nerve for the overlying skin. 



The ramulus last described receives some fibres from 

 the r. mandibularis VII {m. VII. 8) and these enter the 

 largest ramulus of this group from the 14th infra -orbital 

 branch, which will next be described. This nerve runs 

 forward in several branchlets along the outer face of the 

 articular and dentary bones to the tip of the mandible (its 

 distal portion not shown on the plot). It supplies the 

 skin adjacent the mandibular canal for its entire length. 

 Its fibres were also definitely traced to three very minute 

 naked sense organs [in. p. /., Fig. 5) lying over the man- 

 dibular canal, one over the fifth canal organ, one at the 

 fourth pore and one behind the fourth canal organ. There 

 may also be other similar organs in the same vicinity, as 

 they are minute and very slight imperfections in the sec- 

 tions might obscure them. The first one mentioned was 

 found only on the right side of the specimen figured, 

 though probably present on both sides. 



These organs resemble in structure the similar organs 

 lying over the opercular canal, rather than the terminal 

 buds on the lips supplied by the r. mandibularis internus 



