434 



JAMES ERNEST KINDRED 



The cartilage of this region of the parachordals has the same 

 relation to the notochord in both Syngnathus and the 5.7-mm. 

 Gasterosteus, but it is not as widely separated from the noto- 

 chord as it is in a 19-mm. Amia (Kindred, '19). This indicates 



f.brc. 



sept, 

 semi. 



rr^br.II 



tf-nch. 



Fig. 7 Cross-section through the middle part of the otic capsules, 8-mm. 

 Syngnathus. Semidiagrammatic. Camera lucida. X 100. 



Fig. 8 Cross-section through the occipital region, 8-mm Syngnathus. Semi- 

 diagrammatic. Camera lucida. X 100. 



br.II, branchial arch II 



f.bcr.p., fenestra basicranii posterius 



for.IX-X, foramen for IX and X era 



nial nerves 

 nch, notochord 

 ot.c, otic capsule 



ABBREVIATIONS 



pch., parachordal cartilage 

 sept. semi., septum semicircularis lat- 

 eralis 

 ven.j., vena jugularis 

 X, ganglion of vagus nerve 



a precocious growth of the cartilage in this region of Syngnathus. 

 Laterally, the cartilage of each parachordal is confluent with 

 the ventromesial margin of the otic capsule (fig. 7). The carti- 

 lage cells of the parachordals are arranged concentrically^, while 

 those of the otic capsule are in a vertical row. 



