252 Dr. J. D. F. Gilchrist on the 
markedly from the pharyngeal teeth, which form a small 
part of the inner lining of the sac at its anterior end.. They 
bear a close resemblance to the gill-rakers, which in this fish 
are well developed. One of these, which was cut and treated 
in the same way, showed the same structure. It was 2°89 mm. 
in length ; the spines were not, however, slightly curved, as 
in the cesophageal teeth. The conclusion arrived at is that, 
in this case, some of the teeth of the cesophageal sacs are 
teeth of the upper pharyngeals, most of them, however, being 
homologous with gill-rakers probably arising as an extension 
backwards of the epithelium of the last gill-arch. 
Stromateus capensis. 
The cesophageal sacs in this species form an almost 
spherical mass, about 17 mm. in diameter in a fish 200 mm. 
One of the tooth-like processes of the cesophageal sacs of 
Stromateus capensis. Magnification the same as Fig. 1. 
in length, or one and a half times the diameter of the eye. 
It is nearer the branchial region than in the last case, and is 
ba ed o> 
