130 BULLETIN OF THE ESSEX INSTITUTE. 



border of the marginal band. Its dorsal end is free. Just in 

 front of the bend of the antorbital process is an isolated 

 strip of cartilage occupying a diagonal position, one end 

 being dorso-medial and the other ventro-lateral. A small 

 cylindrical rod (tc) extends backward in the median line 

 from the posterior end of the nasal septum and ends freely 

 above the brain, a remnant of the ancestrally complete 

 tegmen cranii. 



The quadrate has its base firmly fused with the otic 

 capsule and trabecula. It is a solid mass projecting down- 

 ward and forward, and presents upon its anterior end a 

 large articular surface for the enormous posterior end of 

 Meckel's cartilage (Fig. 30). Except for a short distance 

 in front of its point of articulation, Meckel's cartilage is of 

 only ordinary size. There are upon each side of the lower 

 jaw three labial cartilages (Ic). As shown in the figure 

 the posterior of these is separated from the jaw and 

 divided into two parts, but this occurred upon the right side 

 only. By mistake the anterior end of the lower jaw was 

 drawn nearly straight instead of curved sharply upward 

 as it should have been. 



The ninth nerve {ix) passes out through a small fora- 

 men a short distance in front of the jugular foramen. 

 Five foramina grouped about the anterior end of the otic 

 capsule open upon the dorso-lateral surface of the skull. 

 I have designated the nerves passing through these fo- 

 ramina in accordance with the work of Pinkus ('94). The 

 third nerve passes through a small foramen (Fig. 30, oc) 

 near the dorsal margin of the trabecula. Just below the 

 foramen for the third is a larofer one for the ramus 

 ophthalmicus profundus of the fifth (77;), and still lower 

 is another for the ramus maxillaris of the fifth {rm). A 

 short distance behind this foramen are the openings of the 

 other two lying close together, one above the other. The 



