256 Description of a Species of Caligus. 



The intestinal fluids are usually light yellow ; occasionally they 

 present a deep wine yellow color, especially below the sternum of 

 the second pair of natatories. Solid vermiform masses of a brown 

 color, are often seen floating in the fluids. 



Along the alimentary canal, there are several small glands, 

 which have a granulous structure and are in general but slightly 

 colored. Their particular functions, are mostly conjectural. 



The central projection between g, g, fig. 12, is the termination 

 of a gland of considerable size, which is situated beneath the pos- 

 terior extremity of the buccal mass, and is usually detached with 

 it, on dissection. It is represented in fig. 9, a, where its size cor- 

 responds to the mouth in fig. 9. When separated from the mouth, 

 a duct may be seen on each side, entering the mouth near the 

 esophagus. Anterior to the mouth, another collection of glands 

 is observed, (fig. 9, b, see also fig. 1,) which also communicate 

 with the mouth by ducts. These are probably salivary glands. 



The esophagus, especially near its base, is furnished with a 

 large number of exceedingly minute, transparent globules, sup- 

 ported on short pedicels, (fig. 10, PI. IV.) These appear to be 

 glands, and their pedicels ducts. 



Below the stomach in the thorax, there are four pairs of glands. 

 One pair of nearly spherical form, are situated at the lower extrem- 

 ity of the stomach, (c, fig. 9.) The second pair, larger, of an 

 oblong form, (d,) occur just below the sternum of the first pair of 

 natatories, and are connected with the intestine by a duct under 

 the following sternum. The third and fourth pairs, (e, f,) are sit- 

 uated on the enlargement of the intestine, below the sternum of 

 the second pair of natatories. The functions of a liver are prob- 

 ably performed by some or all of these glands. 



Two other pairs of small glands are situated in the abdomen, 

 which we presume to be connected with the intestine ; we have 

 not however distinguished their ducts, neither have we by dissec- 

 tions obtained more than one of them separate from the body. 

 They are possibly urinary glands. 



The Caligi have heretofore been supposed to live by sucking 

 the blood of the fish on which they are found. It is however 

 apparent from the structure of the mouth, that they are wholly 

 unfitted for this mode of life. There is no organ which can per- 

 form the functions of a sucker. Moreover, we have never detect- 



