THE DISCOBOLI. 29 



well as a substitute for a tongue. It is to this that reference is made 

 iu the above quotation. Following the glossohyal toward obsolescence, 

 the basibranchials are reduced to little rounded lumps of cartilage, hardly 

 longer than broad. Between the pharyngeals and the hyals the lower 

 ends of the branchial arches are compressed and packed close upon eacli 

 other. In individuals there is some irregularity in the development of 

 the lower elements of the arches. That at hand discloses a minute basi- 

 branchial above the urohyal, a second between the first hypobranchials 

 and extending as a wedge partly between the second pair, and a third 

 at the ends of the hypobranchials of the third arch. A small lump in 

 front of each of the lower pharyngeals indicates the position of the 

 hypobranchials of the fourth pair of arches. Through compression of 

 the lower ends of the arches into such a limited space, the distance 

 from the mouth to the esophagus is made quite short. The passages 

 between the gills extend the length of the ceratobranchials. Each of 

 the latter, except in the fourth arch, is provided with two series of 

 seven to nine gill teeth at each side; the posterior arch has but a 

 single series. These teeth are thick, short, simple, pointed cartilaginous 

 structures, on some of which the points are hooked. All of the epi- 

 branchials are short. Those of the first arches are small, and composed 

 of a basal portion as broad as long, and a slender apical prolongation 

 of about the same length as the base. No upper epibranchial is found. 

 The lower pharyngeals are elongate club-shaped, and bear a rounded 

 bunch of conical teeth on the anterior fourth of the length; the upper 

 on each side form a single bone, in which the components are indistinct, 

 connected with the epibranchials of the posterior three arches. 



Viscera. — The esophagus is short, and has a slight constriction at the 

 stomach. The stomacli is large, and shaped somewhat like a horse-shoe; 

 its cardiac portion lies in the upper part of the body cavity, and turns 

 slightly to the left, while the pyloric section lies below, and turns for- 

 ward and to the right. Around the pylorus there are, in this specimen, 

 forty-two elongate caeca, which unite and reunite in such a manner as 

 to form six parcels, each opening into the intestine by a separate aper- 

 ture immediately below the valve. The intestine is about twice the total 

 length ; the rectum is larger than the balance, and separated from it by 

 a valvular fold. In shape the liver is subtriangular ; it is moderately 



