﻿44 The Philippine Journal of Science 1914 



the ceratobranchials (63) of the 4th arch, the posterodorsal por- 

 tion of the 4th basibranchial (17) , and the hypobranchials of the 

 3d arch on the opposite side. Distally they articulate with the 

 ceratobranchials (63) of the 3d arch. The anterior process 

 articulates with the proximal ventral epicondyle of the hypo- 

 branchials of the 2d branchial arch and with the anterior process 

 of the hypobranchials of the 3d arch on the opposite side. 



Unlike other hypobranchials, those of the 3d arch have areas 

 of cardiform teeth on the posterodorsal side which are firmly 

 fixed and not detachable. Also, these areas are much larger than 

 the detachable areas of the other hypobranchials and modified 

 epibranchials (74) of the 1st branchial arch. There are no 

 hypobranchials in the 4th branchial arch. 



In Plate XV the hypobranchials are still articulated, and 

 are shown from the dorsal side. 



Upper or superior pharyngeals (23). These are designated 

 by 23 2 , 23 3 , 23 4 , referring to the different branchial arches, 

 23 2 articulates with the epibranchial (64) of the 2d arch, 23 3 

 articulates with the epibranchial (64) of the 3d arch, and 23* 

 articulates with the epibranchial (64) of the 4th arch. In 

 Plates XV and XVI the upper pharyngeals are shown moved 

 outwardly and posteriorly, together with the epibranchials (64), 

 on the articulation of the epibranchials and the ceratobranchials 

 (63) as a hinge. In the latter plate they are not articulated, 

 while they are in the former. In their natural position the 

 upper pharyngeals lie dorsad of the inferior pharyngeals (25), 

 so that their toothed surfaces lie together. The upper pharyn- 

 geals of the 2d and 3d arches and the epibranchials (64) of 

 the 2d arch articulate with the ventral side of the basioccipital 

 (69). 



In some specimens examined, certain of the teeth of the 

 superior pharyngeals of the 4th arch were seen to be growing 

 from the sides of large sockets, presumably of larger, more 

 mature teeth already shed. 



Lower or inferior pharyngeals (25). These are articulated 

 anteriorly and laterally with the ceratobranchials (63) of the 

 4th branchial arch, the posterodorsal portion lying interior to 

 the ceratobranchials (63). As seen in Plate XVI, they are 

 provided with teeth which increase in size posteriorly. They 

 are very small anteriorly and very large posteriorly. Along 

 the posterior margin small teeth are seen in large sockets — 

 the same condition existing as is described in No. 23. Plate 

 VI, fig. 1, and Plates XV and XVI illustrate these. 



