34 



University of California Publications in Zoology. [Vol.8 



Anterior teeth 3 to 7, closely set, conical, and converging distally. 

 Posterior teeth 3 to 8, seldom closely set, and usually shorter than anterior 

 teeth. There is considerable evidence that tends to show that the older 

 specimens very frequently lose .their teeth. 



Seizing jaws (pi. 4, fig. 29) 4 to 8. Curvature about 57 per cent. Points 

 very blunt, with oval base, and imbedded about 25 per cent of their 

 height into shaft. Back of point has greater curvature than back of 

 shaft, but edge of point and edge of shaft have the same curvature, so 

 that apex of point lies nearer edge of ,jaw. Near its base the point 

 makes an acute angle with both baclv and edge of shaft. Base of point 

 and top of shaft converge in approaching back of jaw. Pulp-canal slightly 

 displaced toward back of shaft. Pulp evenly distributed throughout 

 canal, extending into the point from 52 to 64 per cent of its height. 



TABLE 4 



Measurements of Sagitta lyra'^ 



1 All measurements made in jier cent of total length of animal. 



2 The length of the anterior fin is measured from its most anterior 

 extremity to the narrowest point of the fin-bridge. The posterior fin is 

 measured from the same point, and the width of the bridge is taken at 

 its narrowest point. The distance from anterior fin to ventral ganglion 

 in every case has been zero. 



3 Per cent of posterior fin in front of tail-septum. 



